[409] | 1 | /* |
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| 2 | * Copyright 1996, University Corporation for Atmospheric Research |
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| 3 | * See netcdf/COPYRIGHT file for copying and redistribution conditions. |
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| 4 | */ |
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| 5 | /* $Id: posixio.c,v 1.89 2010/05/22 21:59:08 dmh Exp $ */ |
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| 6 | |
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| 7 | /* For MinGW Build */ |
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| 8 | #if defined(_WIN32) || defined(_WIN64) |
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| 9 | #include <windows.h> |
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| 10 | #include <winbase.h> |
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| 11 | #include <io.h> |
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| 12 | #define fstat64 fstat |
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| 13 | #define lseek64 lseek |
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| 14 | #endif |
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| 15 | |
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| 16 | #include <config.h> |
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| 17 | #include <assert.h> |
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| 18 | #include <stdlib.h> |
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| 19 | #include <errno.h> |
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| 20 | #ifndef ENOERR |
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| 21 | #define ENOERR 0 |
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| 22 | #endif |
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| 23 | #include <sys/types.h> |
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| 24 | #include <sys/stat.h> |
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| 25 | #include <fcntl.h> |
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| 26 | #include <string.h> |
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| 27 | #ifdef _MSC_VER /* Microsoft Compilers */ |
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| 28 | #include <io.h> |
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| 29 | #else |
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| 30 | #include <unistd.h> |
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| 31 | #endif |
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| 32 | #ifndef HAVE_SSIZE_T |
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| 33 | #define ssize_t int |
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| 34 | #endif |
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| 35 | |
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| 36 | #ifndef SEEK_SET |
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| 37 | #define SEEK_SET 0 |
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| 38 | #define SEEK_CUR 1 |
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| 39 | #define SEEK_END 2 |
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| 40 | #endif |
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| 41 | |
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| 42 | #include "ncio.h" |
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| 43 | #include "fbits.h" |
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| 44 | #include "rnd.h" |
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| 45 | |
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| 46 | /* #define INSTRUMENT 1 */ |
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| 47 | #if INSTRUMENT /* debugging */ |
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| 48 | #undef NDEBUG |
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| 49 | #include <stdio.h> |
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| 50 | /*#include "instr.h"*/ |
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| 51 | #endif |
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| 52 | |
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| 53 | #undef MIN /* system may define MIN somewhere and complain */ |
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| 54 | #define MIN(mm,nn) (((mm) < (nn)) ? (mm) : (nn)) |
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| 55 | |
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| 56 | #if !defined(NDEBUG) && !defined(X_INT_MAX) |
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| 57 | #define X_INT_MAX 2147483647 |
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| 58 | #endif |
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| 59 | |
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| 60 | #if 0 /* !defined(NDEBUG) && !defined(X_ALIGN) */ |
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| 61 | #define X_ALIGN 4 |
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| 62 | #else |
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| 63 | #undef X_ALIGN |
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| 64 | #endif |
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| 65 | |
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| 66 | /* These are needed on mingw to get a dll to compile. They really |
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| 67 | * should be provided in sys/stats.h, but what the heck. Let's not be |
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| 68 | * too picky! */ |
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| 69 | #ifndef S_IRGRP |
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| 70 | #define S_IRGRP 0000040 |
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| 71 | #endif |
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| 72 | #ifndef S_IROTH |
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| 73 | #define S_IROTH 0000004 |
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| 74 | #endif |
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| 75 | #ifndef S_IWGRP |
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| 76 | #define S_IWGRP 0000020 |
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| 77 | #endif |
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| 78 | #ifndef S_IWOTH |
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| 79 | #define S_IWOTH 0000002 |
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| 80 | #endif |
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| 81 | |
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| 82 | /*Forward*/ |
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| 83 | static int ncio_px_filesize(ncio *nciop, off_t *filesizep); |
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| 84 | static int ncio_px_pad_length(ncio *nciop, off_t length); |
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| 85 | static int ncio_px_close(ncio *nciop, int doUnlink); |
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| 86 | static int ncio_spx_close(ncio *nciop, int doUnlink); |
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| 87 | |
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| 88 | |
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| 89 | /* |
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| 90 | * Define the following for debugging. |
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| 91 | */ |
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| 92 | /* #define ALWAYS_NC_SHARE 1 */ |
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| 93 | |
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| 94 | /* Begin OS */ |
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| 95 | |
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| 96 | #ifndef POSIXIO_DEFAULT_PAGESIZE |
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| 97 | #define POSIXIO_DEFAULT_PAGESIZE 4096 |
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| 98 | #endif |
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| 99 | /* |
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| 100 | * What is the system pagesize? |
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| 101 | */ |
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| 102 | static size_t |
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| 103 | pagesize(void) |
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| 104 | { |
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| 105 | size_t pgsz; |
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| 106 | #if defined(_WIN32) || defined(_WIN64) |
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| 107 | SYSTEM_INFO info; |
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| 108 | #endif |
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| 109 | /* Hmm, aren't standards great? */ |
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| 110 | #if defined(_SC_PAGE_SIZE) && !defined(_SC_PAGESIZE) |
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| 111 | #define _SC_PAGESIZE _SC_PAGE_SIZE |
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| 112 | #endif |
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| 113 | |
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| 114 | /* For MinGW Builds */ |
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| 115 | #if defined(_WIN32) || defined(_WIN64) |
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| 116 | GetSystemInfo(&info); |
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| 117 | pgsz = (size_t)info.dwPageSize; |
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| 118 | #elif defined(_SC_PAGESIZE) |
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| 119 | pgsz = (size_t)sysconf(_SC_PAGESIZE); |
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| 120 | #elif defined(HAVE_GETPAGESIZE) |
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| 121 | pgsz = (size_t) getpagesize(); |
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| 122 | #endif |
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| 123 | if(pgsz > 0) |
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| 124 | return (size_t) pgsz; |
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| 125 | return (size_t)POSIXIO_DEFAULT_PAGESIZE; |
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| 126 | } |
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| 127 | |
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| 128 | /* |
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| 129 | * What is the preferred I/O block size? |
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| 130 | */ |
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| 131 | static size_t |
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| 132 | blksize(int fd) |
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| 133 | { |
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| 134 | #if defined(HAVE_ST_BLKSIZE) |
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| 135 | struct stat sb; |
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| 136 | if (fstat(fd, &sb) > -1) |
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| 137 | { |
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| 138 | if(sb.st_blksize >= 8192) |
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| 139 | return (size_t) sb.st_blksize; |
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| 140 | return 8192; |
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| 141 | } |
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| 142 | /* else, silent in the face of error */ |
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| 143 | #endif |
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| 144 | return (size_t) 2 * pagesize(); |
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| 145 | } |
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| 146 | |
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| 147 | |
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| 148 | /* |
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| 149 | * Sortof like ftruncate, except won't make the |
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| 150 | * file shorter. |
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| 151 | */ |
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| 152 | static int |
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| 153 | fgrow(const int fd, const off_t len) |
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| 154 | { |
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| 155 | struct stat sb; |
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| 156 | if (fstat(fd, &sb) < 0) |
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| 157 | return errno; |
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| 158 | if (len < sb.st_size) |
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| 159 | return ENOERR; |
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| 160 | { |
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| 161 | const long dumb = 0; |
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| 162 | /* we don't use ftruncate() due to problem with FAT32 file systems */ |
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| 163 | /* cache current position */ |
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| 164 | const off_t pos = lseek(fd, 0, SEEK_CUR); |
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| 165 | if(pos < 0) |
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| 166 | return errno; |
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| 167 | if (lseek(fd, len-sizeof(dumb), SEEK_SET) < 0) |
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| 168 | return errno; |
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| 169 | if(write(fd, &dumb, sizeof(dumb)) < 0) |
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| 170 | return errno; |
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| 171 | if (lseek(fd, pos, SEEK_SET) < 0) |
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| 172 | return errno; |
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| 173 | } |
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| 174 | return ENOERR; |
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| 175 | } |
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| 176 | |
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| 177 | |
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| 178 | /* |
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| 179 | * Sortof like ftruncate, except won't make the file shorter. Differs |
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| 180 | * from fgrow by only writing one byte at designated seek position, if |
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| 181 | * needed. |
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| 182 | */ |
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| 183 | static int |
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| 184 | fgrow2(const int fd, const off_t len) |
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| 185 | { |
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| 186 | struct stat sb; |
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| 187 | if (fstat(fd, &sb) < 0) |
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| 188 | return errno; |
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| 189 | if (len <= sb.st_size) |
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| 190 | return ENOERR; |
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| 191 | { |
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| 192 | const char dumb = 0; |
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| 193 | /* we don't use ftruncate() due to problem with FAT32 file systems */ |
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| 194 | /* cache current position */ |
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| 195 | const off_t pos = lseek(fd, 0, SEEK_CUR); |
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| 196 | if(pos < 0) |
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| 197 | return errno; |
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| 198 | if (lseek(fd, len-1, SEEK_SET) < 0) |
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| 199 | return errno; |
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| 200 | if(write(fd, &dumb, sizeof(dumb)) < 0) |
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| 201 | return errno; |
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| 202 | if (lseek(fd, pos, SEEK_SET) < 0) |
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| 203 | return errno; |
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| 204 | } |
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| 205 | return ENOERR; |
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| 206 | } |
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| 207 | /* End OS */ |
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| 208 | /* Begin px */ |
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| 209 | |
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| 210 | /* The px_ functions are for posix systems, when NC_SHARE is not in |
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| 211 | effect. */ |
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| 212 | |
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| 213 | /* Write out a "page" of data to the file. The size of the page |
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| 214 | (i.e. the extent) varies. |
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| 215 | |
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| 216 | nciop - pointer to the file metadata. |
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| 217 | offset - where in the file should this page be written. |
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| 218 | extent - how many bytes should be written. |
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| 219 | vp - pointer to the data to write. |
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| 220 | posp - pointer to current position in file, updated after write. |
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| 221 | */ |
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| 222 | static int |
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| 223 | px_pgout(ncio *const nciop, |
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| 224 | off_t const offset, const size_t extent, |
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| 225 | void *const vp, off_t *posp) |
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| 226 | { |
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| 227 | ssize_t partial; |
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| 228 | size_t nextent; |
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| 229 | char *nvp; |
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| 230 | #ifdef X_ALIGN |
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| 231 | assert(offset % X_ALIGN == 0); |
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| 232 | #endif |
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| 233 | |
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| 234 | assert(*posp == OFF_NONE || *posp == lseek(nciop->fd, 0, SEEK_CUR)); |
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| 235 | |
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| 236 | if(*posp != offset) |
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| 237 | { |
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| 238 | if(lseek(nciop->fd, offset, SEEK_SET) != offset) |
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| 239 | { |
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| 240 | return errno; |
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| 241 | } |
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| 242 | *posp = offset; |
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| 243 | } |
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| 244 | /* Old write, didn't handle partial writes correctly */ |
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| 245 | /* if(write(nciop->fd, vp, extent) != (ssize_t) extent) */ |
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| 246 | /* { */ |
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| 247 | /* return errno; */ |
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| 248 | /* } */ |
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| 249 | nextent = extent; |
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| 250 | nvp = vp; |
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| 251 | while((partial = write(nciop->fd, nvp, nextent)) != -1) { |
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| 252 | if(partial == nextent) |
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| 253 | break; |
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| 254 | nvp += partial; |
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| 255 | nextent -= partial; |
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| 256 | } |
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| 257 | if(partial == -1) |
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| 258 | return errno; |
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| 259 | *posp += extent; |
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| 260 | |
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| 261 | return ENOERR; |
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| 262 | } |
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| 263 | |
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| 264 | /* Read in a page of data. |
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| 265 | |
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| 266 | nciop - a pointer to the ncio struct for this file. |
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| 267 | offset - byte offset in file where read starts. |
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| 268 | extent - the size of the page that will be read. |
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| 269 | vp - a pointer to where the data will end up. |
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| 270 | nreadp - returned number of bytes actually read (may be less than extent). |
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| 271 | posp - pointer to current position in file, updated after read. |
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| 272 | */ |
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| 273 | static int |
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| 274 | px_pgin(ncio *const nciop, |
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| 275 | off_t const offset, const size_t extent, |
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| 276 | void *const vp, size_t *nreadp, off_t *posp) |
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| 277 | { |
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| 278 | int status; |
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| 279 | ssize_t nread; |
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| 280 | |
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| 281 | #ifdef X_ALIGN |
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| 282 | assert(offset % X_ALIGN == 0); |
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| 283 | assert(extent % X_ALIGN == 0); |
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| 284 | #endif |
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| 285 | |
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| 286 | assert(*posp == OFF_NONE || *posp == lseek(nciop->fd, 0, SEEK_CUR)); |
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| 287 | |
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| 288 | if(*posp != offset) |
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| 289 | { |
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| 290 | if(lseek(nciop->fd, offset, SEEK_SET) != offset) |
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| 291 | { |
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| 292 | status = errno; |
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| 293 | return status; |
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| 294 | } |
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| 295 | *posp = offset; |
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| 296 | } |
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| 297 | |
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| 298 | errno = 0; |
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| 299 | nread = read(nciop->fd, vp, extent); |
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| 300 | if(nread != (ssize_t) extent) |
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| 301 | { |
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| 302 | status = errno; |
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| 303 | if(nread == -1 || status != ENOERR) |
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| 304 | return status; |
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| 305 | /* else it's okay we read less than asked for */ |
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| 306 | (void) memset((char *)vp + nread, 0, (ssize_t)extent - nread); |
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| 307 | } |
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| 308 | *nreadp = nread; |
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| 309 | *posp += nread; |
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| 310 | |
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| 311 | return ENOERR; |
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| 312 | } |
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| 313 | |
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| 314 | /* This struct is for POSIX systems, with NC_SHARE not in effect. If |
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| 315 | NC_SHARE is used, see ncio_spx. |
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| 316 | |
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| 317 | blksz - block size for reads and writes to file. |
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| 318 | pos - current read/write position in file. |
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| 319 | bf_offset - file offset corresponding to start of memory buffer |
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| 320 | bf_extent - number of bytes in I/O request |
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| 321 | bf_cnt - number of bytes available in buffer |
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| 322 | bf_base - pointer to beginning of buffer. |
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| 323 | bf_rflags - buffer region flags (defined in ncio.h) tell the lock |
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| 324 | status, read/write permissions, and modification status of regions |
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| 325 | of data in the buffer. |
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| 326 | bf_refcount - buffer reference count. |
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| 327 | slave - used in moves. |
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| 328 | */ |
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| 329 | typedef struct ncio_px { |
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| 330 | size_t blksz; |
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| 331 | off_t pos; |
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| 332 | /* buffer */ |
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| 333 | off_t bf_offset; |
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| 334 | size_t bf_extent; |
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| 335 | size_t bf_cnt; |
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| 336 | void *bf_base; |
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| 337 | int bf_rflags; |
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| 338 | int bf_refcount; |
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| 339 | /* chain for double buffering in px_move */ |
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| 340 | struct ncio_px *slave; |
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| 341 | } ncio_px; |
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| 342 | |
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| 343 | |
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| 344 | /*ARGSUSED*/ |
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| 345 | /* This function indicates the file region starting at offset may be |
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| 346 | released. |
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| 347 | |
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| 348 | This is for POSIX, without NC_SHARE. If called with RGN_MODIFIED |
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| 349 | flag, sets the modified flag in pxp->bf_rflags and decrements the |
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| 350 | reference count. |
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| 351 | |
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| 352 | pxp - pointer to posix non-share ncio_px struct. |
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| 353 | |
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| 354 | offset - file offset for beginning of to region to be |
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| 355 | released. |
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| 356 | |
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| 357 | rflags - only RGN_MODIFIED is relevent to this function, others ignored |
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| 358 | */ |
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| 359 | static int |
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| 360 | px_rel(ncio_px *const pxp, off_t offset, int rflags) |
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| 361 | { |
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| 362 | assert(pxp->bf_offset <= offset |
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| 363 | && offset < pxp->bf_offset + (off_t) pxp->bf_extent); |
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| 364 | assert(pIf(fIsSet(rflags, RGN_MODIFIED), |
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| 365 | fIsSet(pxp->bf_rflags, RGN_WRITE))); |
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| 366 | |
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| 367 | if(fIsSet(rflags, RGN_MODIFIED)) |
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| 368 | { |
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| 369 | fSet(pxp->bf_rflags, RGN_MODIFIED); |
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| 370 | } |
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| 371 | pxp->bf_refcount--; |
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| 372 | |
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| 373 | return ENOERR; |
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| 374 | } |
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| 375 | |
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| 376 | /* This function indicates the file region starting at offset may be |
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| 377 | released. Each read or write to the file is bracketed by a call to |
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| 378 | the "get" region function and a call to the "rel" region function. |
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| 379 | If you only read from the memory region, release it with a flag of |
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| 380 | 0, if you modify the region, release it with a flag of |
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| 381 | RGN_MODIFIED. |
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| 382 | |
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| 383 | For POSIX system, without NC_SHARE, this becomes the rel function |
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| 384 | pointed to by the ncio rel function pointer. It mearly checks for |
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| 385 | file write permission, then calls px_rel to do everything. |
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| 386 | |
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| 387 | nciop - pointer to ncio struct. |
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| 388 | offset - num bytes from beginning of buffer to region to be |
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| 389 | released. |
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| 390 | rflags - only RGN_MODIFIED is relevent to this function, others ignored |
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| 391 | */ |
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| 392 | static int |
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| 393 | ncio_px_rel(ncio *const nciop, off_t offset, int rflags) |
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| 394 | { |
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| 395 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
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| 396 | |
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| 397 | if(fIsSet(rflags, RGN_MODIFIED) && !fIsSet(nciop->ioflags, NC_WRITE)) |
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| 398 | return EPERM; /* attempt to write readonly file */ |
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| 399 | |
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| 400 | return px_rel(pxp, offset, rflags); |
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| 401 | } |
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| 402 | |
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| 403 | /* POSIX get. This will "make a region available." Since we're using |
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| 404 | buffered IO, this means that if needed, we'll fetch a new page from |
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| 405 | the file, otherwise, just return a pointer to what's in memory |
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| 406 | already. |
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| 407 | |
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| 408 | nciop - pointer to ncio struct, containing file info. |
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| 409 | pxp - pointer to ncio_px struct, which contains special metadate |
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| 410 | for posix files without NC_SHARE. |
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| 411 | offset - start byte of region to get. |
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| 412 | extent - how many bytes to read. |
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| 413 | rflags - One of the RGN_* flags defined in ncio.h. |
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| 414 | vpp - pointer to pointer that will recieve data. |
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| 415 | |
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| 416 | NOTES: |
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| 417 | |
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| 418 | * For blkoffset round offset down to the nearest pxp->blksz. This |
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| 419 | provides the offset (in bytes) to the beginning of the block that |
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| 420 | holds the current offset. |
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| 421 | |
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| 422 | * diff tells how far into the current block we are. |
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| 423 | |
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| 424 | * For blkextent round up to the number of bytes at the beginning of |
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| 425 | the next block, after the one that holds our current position, plus |
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| 426 | whatever extra (i.e. the extent) that we are about to grab. |
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| 427 | |
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| 428 | * The blkextent can't be more than twice the pxp->blksz. That's |
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| 429 | because the pxp->blksize is the sizehint, and in ncio_px_init2 the |
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| 430 | buffer (pointed to by pxp->bf-base) is allocated with 2 * |
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| 431 | *sizehintp. This is checked (unneccesarily) more than once in |
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| 432 | asserts. |
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| 433 | |
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| 434 | * If this is called on a newly opened file, pxp->bf_offset will be |
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| 435 | OFF_NONE and we'll jump to label pgin to immediately read in a |
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| 436 | page. |
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| 437 | */ |
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| 438 | static int |
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| 439 | px_get(ncio *const nciop, ncio_px *const pxp, |
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| 440 | off_t offset, size_t extent, |
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| 441 | int rflags, |
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| 442 | void **const vpp) |
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| 443 | { |
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| 444 | int status = ENOERR; |
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| 445 | |
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| 446 | const off_t blkoffset = _RNDDOWN(offset, (off_t)pxp->blksz); |
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| 447 | off_t diff = (size_t)(offset - blkoffset); |
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| 448 | off_t blkextent = _RNDUP(diff + extent, pxp->blksz); |
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| 449 | |
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| 450 | assert(extent != 0); |
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| 451 | assert(extent < X_INT_MAX); /* sanity check */ |
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| 452 | assert(offset >= 0); /* sanity check */ |
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| 453 | |
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| 454 | if(2 * pxp->blksz < blkextent) |
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| 455 | return E2BIG; /* TODO: temporary kludge */ |
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| 456 | if(pxp->bf_offset == OFF_NONE) |
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| 457 | { |
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| 458 | /* Uninitialized */ |
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| 459 | if(pxp->bf_base == NULL) |
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| 460 | { |
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| 461 | assert(pxp->bf_extent == 0); |
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| 462 | assert(blkextent <= 2 * pxp->blksz); |
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| 463 | pxp->bf_base = malloc(2 * pxp->blksz); |
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| 464 | if(pxp->bf_base == NULL) |
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| 465 | return ENOMEM; |
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| 466 | } |
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| 467 | goto pgin; |
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| 468 | } |
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| 469 | /* else */ |
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| 470 | assert(blkextent <= 2 * pxp->blksz); |
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| 471 | |
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| 472 | if(blkoffset == pxp->bf_offset) |
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| 473 | { |
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| 474 | /* hit */ |
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| 475 | if(blkextent > pxp->bf_extent) |
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| 476 | { |
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| 477 | /* page in upper */ |
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| 478 | void *const middle = |
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| 479 | (void *)((char *)pxp->bf_base + pxp->blksz); |
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| 480 | assert(pxp->bf_extent == pxp->blksz); |
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| 481 | status = px_pgin(nciop, |
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| 482 | pxp->bf_offset + (off_t)pxp->blksz, |
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| 483 | pxp->blksz, |
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| 484 | middle, |
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| 485 | &pxp->bf_cnt, |
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| 486 | &pxp->pos); |
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| 487 | if(status != ENOERR) |
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| 488 | return status; |
---|
| 489 | pxp->bf_extent = 2 * pxp->blksz; |
---|
| 490 | pxp->bf_cnt += pxp->blksz; |
---|
| 491 | } |
---|
| 492 | goto done; |
---|
| 493 | } |
---|
| 494 | /* else */ |
---|
| 495 | |
---|
| 496 | if(pxp->bf_extent > pxp->blksz |
---|
| 497 | && blkoffset == pxp->bf_offset + (off_t)pxp->blksz) |
---|
| 498 | { |
---|
| 499 | /* hit in upper half */ |
---|
| 500 | if(blkextent == pxp->blksz) |
---|
| 501 | { |
---|
| 502 | /* all in upper half, no fault needed */ |
---|
| 503 | diff += pxp->blksz; |
---|
| 504 | goto done; |
---|
| 505 | } |
---|
| 506 | /* else */ |
---|
| 507 | if(pxp->bf_cnt > pxp->blksz) |
---|
| 508 | { |
---|
| 509 | /* data in upper half */ |
---|
| 510 | void *const middle = |
---|
| 511 | (void *)((char *)pxp->bf_base + pxp->blksz); |
---|
| 512 | assert(pxp->bf_extent == 2 * pxp->blksz); |
---|
| 513 | if(fIsSet(pxp->bf_rflags, RGN_MODIFIED)) |
---|
| 514 | { |
---|
| 515 | /* page out lower half */ |
---|
| 516 | assert(pxp->bf_refcount <= 0); |
---|
| 517 | status = px_pgout(nciop, |
---|
| 518 | pxp->bf_offset, |
---|
| 519 | pxp->blksz, |
---|
| 520 | pxp->bf_base, |
---|
| 521 | &pxp->pos); |
---|
| 522 | if(status != ENOERR) |
---|
| 523 | return status; |
---|
| 524 | } |
---|
| 525 | pxp->bf_cnt -= pxp->blksz; |
---|
| 526 | /* copy upper half into lower half */ |
---|
| 527 | (void) memcpy(pxp->bf_base, middle, pxp->bf_cnt); |
---|
| 528 | } |
---|
| 529 | else /* added to fix nofill bug */ |
---|
| 530 | { |
---|
| 531 | assert(pxp->bf_extent == 2 * pxp->blksz); |
---|
| 532 | /* still have to page out lower half, if modified */ |
---|
| 533 | if(fIsSet(pxp->bf_rflags, RGN_MODIFIED)) |
---|
| 534 | { |
---|
| 535 | assert(pxp->bf_refcount <= 0); |
---|
| 536 | status = px_pgout(nciop, |
---|
| 537 | pxp->bf_offset, |
---|
| 538 | pxp->blksz, |
---|
| 539 | pxp->bf_base, |
---|
| 540 | &pxp->pos); |
---|
| 541 | if(status != ENOERR) |
---|
| 542 | return status; |
---|
| 543 | } |
---|
| 544 | } |
---|
| 545 | pxp->bf_offset = blkoffset; |
---|
| 546 | /* pxp->bf_extent = pxp->blksz; */ |
---|
| 547 | |
---|
| 548 | assert(blkextent == 2 * pxp->blksz); |
---|
| 549 | { |
---|
| 550 | /* page in upper */ |
---|
| 551 | void *const middle = |
---|
| 552 | (void *)((char *)pxp->bf_base + pxp->blksz); |
---|
| 553 | status = px_pgin(nciop, |
---|
| 554 | pxp->bf_offset + (off_t)pxp->blksz, |
---|
| 555 | pxp->blksz, |
---|
| 556 | middle, |
---|
| 557 | &pxp->bf_cnt, |
---|
| 558 | &pxp->pos); |
---|
| 559 | if(status != ENOERR) |
---|
| 560 | return status; |
---|
| 561 | pxp->bf_extent = 2 * pxp->blksz; |
---|
| 562 | pxp->bf_cnt += pxp->blksz; |
---|
| 563 | } |
---|
| 564 | goto done; |
---|
| 565 | } |
---|
| 566 | /* else */ |
---|
| 567 | |
---|
| 568 | if(blkoffset == pxp->bf_offset - (off_t)pxp->blksz) |
---|
| 569 | { |
---|
| 570 | /* wants the page below */ |
---|
| 571 | void *const middle = |
---|
| 572 | (void *)((char *)pxp->bf_base + pxp->blksz); |
---|
| 573 | size_t upper_cnt = 0; |
---|
| 574 | if(pxp->bf_cnt > pxp->blksz) |
---|
| 575 | { |
---|
| 576 | /* data in upper half */ |
---|
| 577 | assert(pxp->bf_extent == 2 * pxp->blksz); |
---|
| 578 | if(fIsSet(pxp->bf_rflags, RGN_MODIFIED)) |
---|
| 579 | { |
---|
| 580 | /* page out upper half */ |
---|
| 581 | assert(pxp->bf_refcount <= 0); |
---|
| 582 | status = px_pgout(nciop, |
---|
| 583 | pxp->bf_offset + (off_t)pxp->blksz, |
---|
| 584 | pxp->bf_cnt - pxp->blksz, |
---|
| 585 | middle, |
---|
| 586 | &pxp->pos); |
---|
| 587 | if(status != ENOERR) |
---|
| 588 | return status; |
---|
| 589 | } |
---|
| 590 | pxp->bf_cnt = pxp->blksz; |
---|
| 591 | pxp->bf_extent = pxp->blksz; |
---|
| 592 | } |
---|
| 593 | if(pxp->bf_cnt > 0) |
---|
| 594 | { |
---|
| 595 | /* copy lower half into upper half */ |
---|
| 596 | (void) memcpy(middle, pxp->bf_base, pxp->blksz); |
---|
| 597 | upper_cnt = pxp->bf_cnt; |
---|
| 598 | } |
---|
| 599 | /* read page below into lower half */ |
---|
| 600 | status = px_pgin(nciop, |
---|
| 601 | blkoffset, |
---|
| 602 | pxp->blksz, |
---|
| 603 | pxp->bf_base, |
---|
| 604 | &pxp->bf_cnt, |
---|
| 605 | &pxp->pos); |
---|
| 606 | if(status != ENOERR) |
---|
| 607 | return status; |
---|
| 608 | pxp->bf_offset = blkoffset; |
---|
| 609 | if(upper_cnt != 0) |
---|
| 610 | { |
---|
| 611 | pxp->bf_extent = 2 * pxp->blksz; |
---|
| 612 | pxp->bf_cnt = pxp->blksz + upper_cnt; |
---|
| 613 | } |
---|
| 614 | else |
---|
| 615 | { |
---|
| 616 | pxp->bf_extent = pxp->blksz; |
---|
| 617 | } |
---|
| 618 | goto done; |
---|
| 619 | } |
---|
| 620 | /* else */ |
---|
| 621 | |
---|
| 622 | /* no overlap */ |
---|
| 623 | if(fIsSet(pxp->bf_rflags, RGN_MODIFIED)) |
---|
| 624 | { |
---|
| 625 | assert(pxp->bf_refcount <= 0); |
---|
| 626 | status = px_pgout(nciop, |
---|
| 627 | pxp->bf_offset, |
---|
| 628 | pxp->bf_cnt, |
---|
| 629 | pxp->bf_base, |
---|
| 630 | &pxp->pos); |
---|
| 631 | if(status != ENOERR) |
---|
| 632 | return status; |
---|
| 633 | pxp->bf_rflags = 0; |
---|
| 634 | } |
---|
| 635 | |
---|
| 636 | pgin: |
---|
| 637 | status = px_pgin(nciop, |
---|
| 638 | blkoffset, |
---|
| 639 | blkextent, |
---|
| 640 | pxp->bf_base, |
---|
| 641 | &pxp->bf_cnt, |
---|
| 642 | &pxp->pos); |
---|
| 643 | if(status != ENOERR) |
---|
| 644 | return status; |
---|
| 645 | pxp->bf_offset = blkoffset; |
---|
| 646 | pxp->bf_extent = blkextent; |
---|
| 647 | |
---|
| 648 | done: |
---|
| 649 | extent += diff; |
---|
| 650 | if(pxp->bf_cnt < extent) |
---|
| 651 | pxp->bf_cnt = extent; |
---|
| 652 | assert(pxp->bf_cnt <= pxp->bf_extent); |
---|
| 653 | |
---|
| 654 | pxp->bf_rflags |= rflags; |
---|
| 655 | pxp->bf_refcount++; |
---|
| 656 | |
---|
| 657 | *vpp = (char *)pxp->bf_base + diff; |
---|
| 658 | return ENOERR; |
---|
| 659 | } |
---|
| 660 | |
---|
| 661 | /* Request that the region (offset, extent) be made available through |
---|
| 662 | *vpp. |
---|
| 663 | |
---|
| 664 | This function converts a file region specified by an offset and |
---|
| 665 | extent to a memory pointer. The region may be locked until the |
---|
| 666 | corresponding call to rel(). |
---|
| 667 | |
---|
| 668 | For POSIX systems, without NC_SHARE. This function gets a page of |
---|
| 669 | size extent? |
---|
| 670 | |
---|
| 671 | This is a wrapper for the function px_get, which does all the heavy |
---|
| 672 | lifting. |
---|
| 673 | |
---|
| 674 | nciop - pointer to ncio struct for this file. |
---|
| 675 | offset - offset (from beginning of file?) to the data we want to |
---|
| 676 | read. |
---|
| 677 | extent - the number of bytes to read from the file. |
---|
| 678 | rflags - One of the RGN_* flags defined in ncio.h. |
---|
| 679 | vpp - handle to point at data when it's been read. |
---|
| 680 | */ |
---|
| 681 | static int |
---|
| 682 | ncio_px_get(ncio *const nciop, |
---|
| 683 | off_t offset, size_t extent, |
---|
| 684 | int rflags, |
---|
| 685 | void **const vpp) |
---|
| 686 | { |
---|
| 687 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 688 | |
---|
| 689 | if(fIsSet(rflags, RGN_WRITE) && !fIsSet(nciop->ioflags, NC_WRITE)) |
---|
| 690 | return EPERM; /* attempt to write readonly file */ |
---|
| 691 | |
---|
| 692 | /* reclaim space used in move */ |
---|
| 693 | if(pxp->slave != NULL) |
---|
| 694 | { |
---|
| 695 | if(pxp->slave->bf_base != NULL) |
---|
| 696 | { |
---|
| 697 | free(pxp->slave->bf_base); |
---|
| 698 | pxp->slave->bf_base = NULL; |
---|
| 699 | pxp->slave->bf_extent = 0; |
---|
| 700 | pxp->slave->bf_offset = OFF_NONE; |
---|
| 701 | } |
---|
| 702 | free(pxp->slave); |
---|
| 703 | pxp->slave = NULL; |
---|
| 704 | } |
---|
| 705 | return px_get(nciop, pxp, offset, extent, rflags, vpp); |
---|
| 706 | } |
---|
| 707 | |
---|
| 708 | |
---|
| 709 | /* ARGSUSED */ |
---|
| 710 | static int |
---|
| 711 | px_double_buffer(ncio *const nciop, off_t to, off_t from, |
---|
| 712 | size_t nbytes, int rflags) |
---|
| 713 | { |
---|
| 714 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 715 | int status = ENOERR; |
---|
| 716 | void *src; |
---|
| 717 | void *dest; |
---|
| 718 | |
---|
| 719 | #if INSTRUMENT |
---|
| 720 | fprintf(stderr, "\tdouble_buffr %ld %ld %ld\n", |
---|
| 721 | (long)to, (long)from, (long)nbytes); |
---|
| 722 | #endif |
---|
| 723 | status = px_get(nciop, pxp, to, nbytes, RGN_WRITE, |
---|
| 724 | &dest); |
---|
| 725 | if(status != ENOERR) |
---|
| 726 | return status; |
---|
| 727 | |
---|
| 728 | if(pxp->slave == NULL) |
---|
| 729 | { |
---|
| 730 | pxp->slave = (ncio_px *) malloc(sizeof(ncio_px)); |
---|
| 731 | if(pxp->slave == NULL) |
---|
| 732 | return ENOMEM; |
---|
| 733 | |
---|
| 734 | pxp->slave->blksz = pxp->blksz; |
---|
| 735 | /* pos done below */ |
---|
| 736 | pxp->slave->bf_offset = pxp->bf_offset; |
---|
| 737 | pxp->slave->bf_extent = pxp->bf_extent; |
---|
| 738 | pxp->slave->bf_cnt = pxp->bf_cnt; |
---|
| 739 | pxp->slave->bf_base = malloc(2 * pxp->blksz); |
---|
| 740 | if(pxp->slave->bf_base == NULL) |
---|
| 741 | return ENOMEM; |
---|
| 742 | (void) memcpy(pxp->slave->bf_base, pxp->bf_base, |
---|
| 743 | pxp->bf_extent); |
---|
| 744 | pxp->slave->bf_rflags = 0; |
---|
| 745 | pxp->slave->bf_refcount = 0; |
---|
| 746 | pxp->slave->slave = NULL; |
---|
| 747 | } |
---|
| 748 | |
---|
| 749 | pxp->slave->pos = pxp->pos; |
---|
| 750 | status = px_get(nciop, pxp->slave, from, nbytes, 0, |
---|
| 751 | &src); |
---|
| 752 | if(status != ENOERR) |
---|
| 753 | return status; |
---|
| 754 | if(pxp->pos != pxp->slave->pos) |
---|
| 755 | { |
---|
| 756 | /* position changed, sync */ |
---|
| 757 | pxp->pos = pxp->slave->pos; |
---|
| 758 | } |
---|
| 759 | |
---|
| 760 | (void) memcpy(dest, src, nbytes); |
---|
| 761 | |
---|
| 762 | (void)px_rel(pxp->slave, from, 0); |
---|
| 763 | (void)px_rel(pxp, to, RGN_MODIFIED); |
---|
| 764 | |
---|
| 765 | return status; |
---|
| 766 | } |
---|
| 767 | |
---|
| 768 | /* Like memmove(), safely move possibly overlapping data. |
---|
| 769 | |
---|
| 770 | Copy one region to another without making anything available to |
---|
| 771 | higher layers. May be just implemented in terms of get() and rel(), |
---|
| 772 | or may be tricky to be efficient. Only used in by nc_enddef() |
---|
| 773 | after redefinition. |
---|
| 774 | |
---|
| 775 | nciop - pointer to ncio struct with file info. |
---|
| 776 | to - src for move? |
---|
| 777 | from - dest for move? |
---|
| 778 | nbytes - number of bytes to move. |
---|
| 779 | rflags - One of the RGN_* flags defined in ncio.h. The only |
---|
| 780 | reasonable flag value is RGN_NOLOCK. |
---|
| 781 | */ |
---|
| 782 | static int |
---|
| 783 | ncio_px_move(ncio *const nciop, off_t to, off_t from, |
---|
| 784 | size_t nbytes, int rflags) |
---|
| 785 | { |
---|
| 786 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 787 | int status = ENOERR; |
---|
| 788 | off_t lower; |
---|
| 789 | off_t upper; |
---|
| 790 | char *base; |
---|
| 791 | size_t diff; |
---|
| 792 | size_t extent; |
---|
| 793 | |
---|
| 794 | if(to == from) |
---|
| 795 | return ENOERR; /* NOOP */ |
---|
| 796 | |
---|
| 797 | if(fIsSet(rflags, RGN_WRITE) && !fIsSet(nciop->ioflags, NC_WRITE)) |
---|
| 798 | return EPERM; /* attempt to write readonly file */ |
---|
| 799 | |
---|
| 800 | rflags &= RGN_NOLOCK; /* filter unwanted flags */ |
---|
| 801 | |
---|
| 802 | if(to > from) |
---|
| 803 | { |
---|
| 804 | /* growing */ |
---|
| 805 | lower = from; |
---|
| 806 | upper = to; |
---|
| 807 | } |
---|
| 808 | else |
---|
| 809 | { |
---|
| 810 | /* shrinking */ |
---|
| 811 | lower = to; |
---|
| 812 | upper = from; |
---|
| 813 | } |
---|
| 814 | diff = (size_t)(upper - lower); |
---|
| 815 | extent = diff + nbytes; |
---|
| 816 | |
---|
| 817 | #if INSTRUMENT |
---|
| 818 | fprintf(stderr, "ncio_px_move %ld %ld %ld %ld %ld\n", |
---|
| 819 | (long)to, (long)from, (long)nbytes, (long)lower, (long)extent); |
---|
| 820 | #endif |
---|
| 821 | if(extent > pxp->blksz) |
---|
| 822 | { |
---|
| 823 | size_t remaining = nbytes; |
---|
| 824 | |
---|
| 825 | if(to > from) |
---|
| 826 | { |
---|
| 827 | off_t frm = from + nbytes; |
---|
| 828 | off_t toh = to + nbytes; |
---|
| 829 | for(;;) |
---|
| 830 | { |
---|
| 831 | size_t loopextent = MIN(remaining, pxp->blksz); |
---|
| 832 | frm -= loopextent; |
---|
| 833 | toh -= loopextent; |
---|
| 834 | |
---|
| 835 | status = px_double_buffer(nciop, toh, frm, |
---|
| 836 | loopextent, rflags) ; |
---|
| 837 | if(status != ENOERR) |
---|
| 838 | return status; |
---|
| 839 | remaining -= loopextent; |
---|
| 840 | |
---|
| 841 | if(remaining == 0) |
---|
| 842 | break; /* normal loop exit */ |
---|
| 843 | } |
---|
| 844 | } |
---|
| 845 | else |
---|
| 846 | { |
---|
| 847 | for(;;) |
---|
| 848 | { |
---|
| 849 | size_t loopextent = MIN(remaining, pxp->blksz); |
---|
| 850 | |
---|
| 851 | status = px_double_buffer(nciop, to, from, |
---|
| 852 | loopextent, rflags) ; |
---|
| 853 | if(status != ENOERR) |
---|
| 854 | return status; |
---|
| 855 | remaining -= loopextent; |
---|
| 856 | |
---|
| 857 | if(remaining == 0) |
---|
| 858 | break; /* normal loop exit */ |
---|
| 859 | to += loopextent; |
---|
| 860 | from += loopextent; |
---|
| 861 | } |
---|
| 862 | } |
---|
| 863 | return ENOERR; |
---|
| 864 | } |
---|
| 865 | |
---|
| 866 | #if INSTRUMENT |
---|
| 867 | fprintf(stderr, "\tncio_px_move small\n"); |
---|
| 868 | #endif |
---|
| 869 | status = px_get(nciop, pxp, lower, extent, RGN_WRITE|rflags, |
---|
| 870 | (void **)&base); |
---|
| 871 | |
---|
| 872 | if(status != ENOERR) |
---|
| 873 | return status; |
---|
| 874 | |
---|
| 875 | if(to > from) |
---|
| 876 | (void) memmove(base + diff, base, nbytes); |
---|
| 877 | else |
---|
| 878 | (void) memmove(base, base + diff, nbytes); |
---|
| 879 | |
---|
| 880 | (void) px_rel(pxp, lower, RGN_MODIFIED); |
---|
| 881 | |
---|
| 882 | return status; |
---|
| 883 | } |
---|
| 884 | |
---|
| 885 | |
---|
| 886 | /* Flush any buffers to disk. May be a no-op on if I/O is unbuffered. |
---|
| 887 | This function is used when NC_SHARE is NOT used. |
---|
| 888 | */ |
---|
| 889 | static int |
---|
| 890 | ncio_px_sync(ncio *const nciop) |
---|
| 891 | { |
---|
| 892 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 893 | int status = ENOERR; |
---|
| 894 | if(fIsSet(pxp->bf_rflags, RGN_MODIFIED)) |
---|
| 895 | { |
---|
| 896 | assert(pxp->bf_refcount <= 0); |
---|
| 897 | status = px_pgout(nciop, pxp->bf_offset, |
---|
| 898 | pxp->bf_cnt, |
---|
| 899 | pxp->bf_base, &pxp->pos); |
---|
| 900 | if(status != ENOERR) |
---|
| 901 | return status; |
---|
| 902 | pxp->bf_rflags = 0; |
---|
| 903 | } |
---|
| 904 | else if (!fIsSet(pxp->bf_rflags, RGN_WRITE)) |
---|
| 905 | { |
---|
| 906 | /* |
---|
| 907 | * The dataset is readonly. Invalidate the buffers so |
---|
| 908 | * that the next ncio_px_get() will actually read data. |
---|
| 909 | */ |
---|
| 910 | pxp->bf_offset = OFF_NONE; |
---|
| 911 | pxp->bf_cnt = 0; |
---|
| 912 | } |
---|
| 913 | return status; |
---|
| 914 | } |
---|
| 915 | |
---|
| 916 | /* Internal function called at close to |
---|
| 917 | free up anything hanging off pvt. |
---|
| 918 | */ |
---|
| 919 | static void |
---|
| 920 | ncio_px_freepvt(void *const pvt) |
---|
| 921 | { |
---|
| 922 | ncio_px *const pxp = (ncio_px *)pvt; |
---|
| 923 | if(pxp == NULL) |
---|
| 924 | return; |
---|
| 925 | |
---|
| 926 | if(pxp->slave != NULL) |
---|
| 927 | { |
---|
| 928 | if(pxp->slave->bf_base != NULL) |
---|
| 929 | { |
---|
| 930 | free(pxp->slave->bf_base); |
---|
| 931 | pxp->slave->bf_base = NULL; |
---|
| 932 | pxp->slave->bf_extent = 0; |
---|
| 933 | pxp->slave->bf_offset = OFF_NONE; |
---|
| 934 | } |
---|
| 935 | free(pxp->slave); |
---|
| 936 | pxp->slave = NULL; |
---|
| 937 | } |
---|
| 938 | |
---|
| 939 | if(pxp->bf_base != NULL) |
---|
| 940 | { |
---|
| 941 | free(pxp->bf_base); |
---|
| 942 | pxp->bf_base = NULL; |
---|
| 943 | pxp->bf_extent = 0; |
---|
| 944 | pxp->bf_offset = OFF_NONE; |
---|
| 945 | } |
---|
| 946 | } |
---|
| 947 | |
---|
| 948 | |
---|
| 949 | /* This is the second half of the ncio initialization. This is called |
---|
| 950 | after the file has actually been opened. |
---|
| 951 | |
---|
| 952 | The most important thing that happens is the allocation of a block |
---|
| 953 | of memory at pxp->bf_base. This is going to be twice the size of |
---|
| 954 | the chunksizehint (rounded up to the nearest sizeof(double)) passed |
---|
| 955 | in from nc__create or nc__open. The rounded chunksizehint (passed |
---|
| 956 | in here in sizehintp) is going to be stored as pxp->blksize. |
---|
| 957 | |
---|
| 958 | According to our "contract" we are not allowed to ask for an extent |
---|
| 959 | larger than this chunksize/sizehint/blksize from the ncio get |
---|
| 960 | function. |
---|
| 961 | |
---|
| 962 | nciop - pointer to the ncio struct |
---|
| 963 | sizehintp - pointer to a size hint that will be rounded up and |
---|
| 964 | passed back to the caller. |
---|
| 965 | isNew - true if this is being called from ncio_create for a new |
---|
| 966 | file. |
---|
| 967 | */ |
---|
| 968 | static int |
---|
| 969 | ncio_px_init2(ncio *const nciop, size_t *sizehintp, int isNew) |
---|
| 970 | { |
---|
| 971 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 972 | const size_t bufsz = 2 * *sizehintp; |
---|
| 973 | |
---|
| 974 | assert(nciop->fd >= 0); |
---|
| 975 | |
---|
| 976 | pxp->blksz = *sizehintp; |
---|
| 977 | |
---|
| 978 | assert(pxp->bf_base == NULL); |
---|
| 979 | |
---|
| 980 | /* this is separate allocation because it may grow */ |
---|
| 981 | pxp->bf_base = malloc(bufsz); |
---|
| 982 | if(pxp->bf_base == NULL) |
---|
| 983 | return ENOMEM; |
---|
| 984 | /* else */ |
---|
| 985 | pxp->bf_cnt = 0; |
---|
| 986 | if(isNew) |
---|
| 987 | { |
---|
| 988 | /* save a read */ |
---|
| 989 | pxp->pos = 0; |
---|
| 990 | pxp->bf_offset = 0; |
---|
| 991 | pxp->bf_extent = bufsz; |
---|
| 992 | (void) memset(pxp->bf_base, 0, pxp->bf_extent); |
---|
| 993 | } |
---|
| 994 | return ENOERR; |
---|
| 995 | } |
---|
| 996 | |
---|
| 997 | |
---|
| 998 | /* This is the first of a two-part initialization of the ncio struct. |
---|
| 999 | Here the rel, get, move, sync, and free function pointers are set |
---|
| 1000 | to their POSIX non-NC_SHARE functions (ncio_px_*). |
---|
| 1001 | |
---|
| 1002 | The ncio_px struct is also partially initialized. |
---|
| 1003 | */ |
---|
| 1004 | static void |
---|
| 1005 | ncio_px_init(ncio *const nciop) |
---|
| 1006 | { |
---|
| 1007 | ncio_px *const pxp = (ncio_px *)nciop->pvt; |
---|
| 1008 | |
---|
| 1009 | *((ncio_relfunc **)&nciop->rel) = ncio_px_rel; /* cast away const */ |
---|
| 1010 | *((ncio_getfunc **)&nciop->get) = ncio_px_get; /* cast away const */ |
---|
| 1011 | *((ncio_movefunc **)&nciop->move) = ncio_px_move; /* cast away const */ |
---|
| 1012 | *((ncio_syncfunc **)&nciop->sync) = ncio_px_sync; /* cast away const */ |
---|
| 1013 | *((ncio_filesizefunc **)&nciop->filesize) = ncio_px_filesize; /* cast away const */ |
---|
| 1014 | *((ncio_pad_lengthfunc **)&nciop->pad_length) = ncio_px_pad_length; /* cast away const */ |
---|
| 1015 | *((ncio_closefunc **)&nciop->close) = ncio_px_close; /* cast away const */ |
---|
| 1016 | |
---|
| 1017 | pxp->blksz = 0; |
---|
| 1018 | pxp->pos = -1; |
---|
| 1019 | pxp->bf_offset = OFF_NONE; |
---|
| 1020 | pxp->bf_extent = 0; |
---|
| 1021 | pxp->bf_rflags = 0; |
---|
| 1022 | pxp->bf_refcount = 0; |
---|
| 1023 | pxp->bf_base = NULL; |
---|
| 1024 | pxp->slave = NULL; |
---|
| 1025 | |
---|
| 1026 | } |
---|
| 1027 | |
---|
| 1028 | /* Begin spx */ |
---|
| 1029 | |
---|
| 1030 | /* This is the struct that gets hung of ncio->pvt(?) when the NC_SHARE |
---|
| 1031 | flag is used. |
---|
| 1032 | */ |
---|
| 1033 | typedef struct ncio_spx { |
---|
| 1034 | off_t pos; |
---|
| 1035 | /* buffer */ |
---|
| 1036 | off_t bf_offset; |
---|
| 1037 | size_t bf_extent; |
---|
| 1038 | size_t bf_cnt; |
---|
| 1039 | void *bf_base; |
---|
| 1040 | } ncio_spx; |
---|
| 1041 | |
---|
| 1042 | |
---|
| 1043 | /*ARGSUSED*/ |
---|
| 1044 | /* This function releases the region specified by offset. |
---|
| 1045 | |
---|
| 1046 | For POSIX system, with NC_SHARE, this becomes the rel function |
---|
| 1047 | pointed to by the ncio rel function pointer. It mearly checks for |
---|
| 1048 | file write permission, then calls px_rel to do everything. |
---|
| 1049 | |
---|
| 1050 | nciop - pointer to ncio struct. |
---|
| 1051 | |
---|
| 1052 | offset - beginning of region. |
---|
| 1053 | |
---|
| 1054 | rflags - One of the RGN_* flags defined in ncio.h. If set to |
---|
| 1055 | RGN_MODIFIED it means that the data in this region were modified, |
---|
| 1056 | and it needs to be written out to the disk immediately (since we |
---|
| 1057 | are not buffering with NC_SHARE on). |
---|
| 1058 | |
---|
| 1059 | */ |
---|
| 1060 | static int |
---|
| 1061 | ncio_spx_rel(ncio *const nciop, off_t offset, int rflags) |
---|
| 1062 | { |
---|
| 1063 | ncio_spx *const pxp = (ncio_spx *)nciop->pvt; |
---|
| 1064 | int status = ENOERR; |
---|
| 1065 | |
---|
| 1066 | assert(pxp->bf_offset <= offset); |
---|
| 1067 | assert(pxp->bf_cnt != 0); |
---|
| 1068 | assert(pxp->bf_cnt <= pxp->bf_extent); |
---|
| 1069 | #ifdef X_ALIGN |
---|
| 1070 | assert(offset < pxp->bf_offset + X_ALIGN); |
---|
| 1071 | assert(pxp->bf_cnt % X_ALIGN == 0 ); |
---|
| 1072 | #endif |
---|
| 1073 | |
---|
| 1074 | if(fIsSet(rflags, RGN_MODIFIED)) |
---|
| 1075 | { |
---|
| 1076 | if(!fIsSet(nciop->ioflags, NC_WRITE)) |
---|
| 1077 | return EPERM; /* attempt to write readonly file */ |
---|
| 1078 | |
---|
| 1079 | status = px_pgout(nciop, pxp->bf_offset, |
---|
| 1080 | pxp->bf_cnt, |
---|
| 1081 | pxp->bf_base, &pxp->pos); |
---|
| 1082 | /* if error, invalidate buffer anyway */ |
---|
| 1083 | } |
---|
| 1084 | pxp->bf_offset = OFF_NONE; |
---|
| 1085 | pxp->bf_cnt = 0; |
---|
| 1086 | return status; |
---|
| 1087 | } |
---|
| 1088 | |
---|
| 1089 | |
---|
| 1090 | /* Request that the region (offset, extent) be made available through |
---|
| 1091 | *vpp. |
---|
| 1092 | |
---|
| 1093 | This function converts a file region specified by an offset and |
---|
| 1094 | extent to a memory pointer. The region may be locked until the |
---|
| 1095 | corresponding call to rel(). |
---|
| 1096 | |
---|
| 1097 | For POSIX systems, with NC_SHARE. |
---|
| 1098 | |
---|
| 1099 | nciop - pointer to ncio struct for this file. |
---|
| 1100 | offset - offset (from beginning of file?) to the data we want to |
---|
| 1101 | read. |
---|
| 1102 | extent - the number of bytes we want. |
---|
| 1103 | rflags - One of the RGN_* flags defined in ncio.h. May be RGN_NOLOCK. |
---|
| 1104 | vpp - handle to point at data when it's been read. |
---|
| 1105 | */ |
---|
| 1106 | static int |
---|
| 1107 | ncio_spx_get(ncio *const nciop, |
---|
| 1108 | off_t offset, size_t extent, |
---|
| 1109 | int rflags, |
---|
| 1110 | void **const vpp) |
---|
| 1111 | { |
---|
| 1112 | ncio_spx *const pxp = (ncio_spx *)nciop->pvt; |
---|
| 1113 | int status = ENOERR; |
---|
| 1114 | #ifdef X_ALIGN |
---|
| 1115 | size_t rem; |
---|
| 1116 | #endif |
---|
| 1117 | |
---|
| 1118 | if(fIsSet(rflags, RGN_WRITE) && !fIsSet(nciop->ioflags, NC_WRITE)) |
---|
| 1119 | return EPERM; /* attempt to write readonly file */ |
---|
| 1120 | |
---|
| 1121 | assert(extent != 0); |
---|
| 1122 | assert(extent < X_INT_MAX); /* sanity check */ |
---|
| 1123 | |
---|
| 1124 | assert(pxp->bf_cnt == 0); |
---|
| 1125 | |
---|
| 1126 | #ifdef X_ALIGN |
---|
| 1127 | rem = (size_t)(offset % X_ALIGN); |
---|
| 1128 | if(rem != 0) |
---|
| 1129 | { |
---|
| 1130 | offset -= rem; |
---|
| 1131 | extent += rem; |
---|
| 1132 | } |
---|
| 1133 | |
---|
| 1134 | { |
---|
| 1135 | const size_t rndup = extent % X_ALIGN; |
---|
| 1136 | if(rndup != 0) |
---|
| 1137 | extent += X_ALIGN - rndup; |
---|
| 1138 | } |
---|
| 1139 | |
---|
| 1140 | assert(offset % X_ALIGN == 0); |
---|
| 1141 | assert(extent % X_ALIGN == 0); |
---|
| 1142 | #endif |
---|
| 1143 | |
---|
| 1144 | if(pxp->bf_extent < extent) |
---|
| 1145 | { |
---|
| 1146 | if(pxp->bf_base != NULL) |
---|
| 1147 | { |
---|
| 1148 | free(pxp->bf_base); |
---|
| 1149 | pxp->bf_base = NULL; |
---|
| 1150 | pxp->bf_extent = 0; |
---|
| 1151 | } |
---|
| 1152 | assert(pxp->bf_extent == 0); |
---|
| 1153 | pxp->bf_base = malloc(extent); |
---|
| 1154 | if(pxp->bf_base == NULL) |
---|
| 1155 | return ENOMEM; |
---|
| 1156 | pxp->bf_extent = extent; |
---|
| 1157 | } |
---|
| 1158 | |
---|
| 1159 | status = px_pgin(nciop, offset, |
---|
| 1160 | extent, |
---|
| 1161 | pxp->bf_base, |
---|
| 1162 | &pxp->bf_cnt, &pxp->pos); |
---|
| 1163 | if(status != ENOERR) |
---|
| 1164 | return status; |
---|
| 1165 | |
---|
| 1166 | pxp->bf_offset = offset; |
---|
| 1167 | |
---|
| 1168 | if(pxp->bf_cnt < extent) |
---|
| 1169 | pxp->bf_cnt = extent; |
---|
| 1170 | |
---|
| 1171 | #ifdef X_ALIGN |
---|
| 1172 | *vpp = (char *)pxp->bf_base + rem; |
---|
| 1173 | #else |
---|
| 1174 | *vpp = pxp->bf_base; |
---|
| 1175 | #endif |
---|
| 1176 | return ENOERR; |
---|
| 1177 | } |
---|
| 1178 | |
---|
| 1179 | |
---|
| 1180 | #if 0 |
---|
| 1181 | /*ARGSUSED*/ |
---|
| 1182 | static int |
---|
| 1183 | strategy(ncio *const nciop, off_t to, off_t offset, |
---|
| 1184 | size_t extent, int rflags) |
---|
| 1185 | { |
---|
| 1186 | static ncio_spx pxp[1]; |
---|
| 1187 | int status = ENOERR; |
---|
| 1188 | #ifdef X_ALIGN |
---|
| 1189 | size_t rem; |
---|
| 1190 | #endif |
---|
| 1191 | |
---|
| 1192 | assert(extent != 0); |
---|
| 1193 | assert(extent < X_INT_MAX); /* sanity check */ |
---|
| 1194 | #if INSTRUMENT |
---|
| 1195 | fprintf(stderr, "strategy %ld at %ld to %ld\n", |
---|
| 1196 | (long)extent, (long)offset, (long)to); |
---|
| 1197 | #endif |
---|
| 1198 | |
---|
| 1199 | |
---|
| 1200 | #ifdef X_ALIGN |
---|
| 1201 | rem = (size_t)(offset % X_ALIGN); |
---|
| 1202 | if(rem != 0) |
---|
| 1203 | { |
---|
| 1204 | offset -= rem; |
---|
| 1205 | extent += rem; |
---|
| 1206 | } |
---|
| 1207 | |
---|
| 1208 | { |
---|
| 1209 | const size_t rndup = extent % X_ALIGN; |
---|
| 1210 | if(rndup != 0) |
---|
| 1211 | extent += X_ALIGN - rndup; |
---|
| 1212 | } |
---|
| 1213 | |
---|
| 1214 | assert(offset % X_ALIGN == 0); |
---|
| 1215 | assert(extent % X_ALIGN == 0); |
---|
| 1216 | #endif |
---|
| 1217 | |
---|
| 1218 | if(pxp->bf_extent < extent) |
---|
| 1219 | { |
---|
| 1220 | if(pxp->bf_base != NULL) |
---|
| 1221 | { |
---|
| 1222 | free(pxp->bf_base); |
---|
| 1223 | pxp->bf_base = NULL; |
---|
| 1224 | pxp->bf_extent = 0; |
---|
| 1225 | } |
---|
| 1226 | assert(pxp->bf_extent == 0); |
---|
| 1227 | pxp->bf_base = malloc(extent); |
---|
| 1228 | if(pxp->bf_base == NULL) |
---|
| 1229 | return ENOMEM; |
---|
| 1230 | pxp->bf_extent = extent; |
---|
| 1231 | } |
---|
| 1232 | |
---|
| 1233 | status = px_pgin(nciop, offset, |
---|
| 1234 | extent, |
---|
| 1235 | pxp->bf_base, |
---|
| 1236 | &pxp->bf_cnt, &pxp->pos); |
---|
| 1237 | if(status != ENOERR) |
---|
| 1238 | return status; |
---|
| 1239 | |
---|
| 1240 | pxp->bf_offset = to; /* TODO: XALIGN */ |
---|
| 1241 | |
---|
| 1242 | if(pxp->bf_cnt < extent) |
---|
| 1243 | pxp->bf_cnt = extent; |
---|
| 1244 | |
---|
| 1245 | status = px_pgout(nciop, pxp->bf_offset, |
---|
| 1246 | pxp->bf_cnt, |
---|
| 1247 | pxp->bf_base, &pxp->pos); |
---|
| 1248 | /* if error, invalidate buffer anyway */ |
---|
| 1249 | pxp->bf_offset = OFF_NONE; |
---|
| 1250 | pxp->bf_cnt = 0; |
---|
| 1251 | return status; |
---|
| 1252 | } |
---|
| 1253 | #endif |
---|
| 1254 | |
---|
| 1255 | /* Copy one region to another without making anything available to |
---|
| 1256 | higher layers. May be just implemented in terms of get() and rel(), |
---|
| 1257 | or may be tricky to be efficient. Only used in by nc_enddef() |
---|
| 1258 | after redefinition. |
---|
| 1259 | |
---|
| 1260 | nciop - pointer to ncio struct for this file. |
---|
| 1261 | to - dest for move? |
---|
| 1262 | from - src for move? |
---|
| 1263 | nbytes - number of bytes to move. |
---|
| 1264 | rflags - One of the RGN_* flags defined in ncio.h. |
---|
| 1265 | */ |
---|
| 1266 | static int |
---|
| 1267 | ncio_spx_move(ncio *const nciop, off_t to, off_t from, |
---|
| 1268 | size_t nbytes, int rflags) |
---|
| 1269 | { |
---|
| 1270 | int status = ENOERR; |
---|
| 1271 | off_t lower = from; |
---|
| 1272 | off_t upper = to; |
---|
| 1273 | char *base; |
---|
| 1274 | size_t diff; |
---|
| 1275 | size_t extent; |
---|
| 1276 | |
---|
| 1277 | rflags &= RGN_NOLOCK; /* filter unwanted flags */ |
---|
| 1278 | |
---|
| 1279 | if(to == from) |
---|
| 1280 | return ENOERR; /* NOOP */ |
---|
| 1281 | |
---|
| 1282 | if(to > from) |
---|
| 1283 | { |
---|
| 1284 | /* growing */ |
---|
| 1285 | lower = from; |
---|
| 1286 | upper = to; |
---|
| 1287 | } |
---|
| 1288 | else |
---|
| 1289 | { |
---|
| 1290 | /* shrinking */ |
---|
| 1291 | lower = to; |
---|
| 1292 | upper = from; |
---|
| 1293 | } |
---|
| 1294 | |
---|
| 1295 | diff = (size_t)(upper - lower); |
---|
| 1296 | extent = diff + nbytes; |
---|
| 1297 | |
---|
| 1298 | status = ncio_spx_get(nciop, lower, extent, RGN_WRITE|rflags, |
---|
| 1299 | (void **)&base); |
---|
| 1300 | |
---|
| 1301 | if(status != ENOERR) |
---|
| 1302 | return status; |
---|
| 1303 | |
---|
| 1304 | if(to > from) |
---|
| 1305 | (void) memmove(base + diff, base, nbytes); |
---|
| 1306 | else |
---|
| 1307 | (void) memmove(base, base + diff, nbytes); |
---|
| 1308 | |
---|
| 1309 | (void) ncio_spx_rel(nciop, lower, RGN_MODIFIED); |
---|
| 1310 | |
---|
| 1311 | return status; |
---|
| 1312 | } |
---|
| 1313 | |
---|
| 1314 | |
---|
| 1315 | /*ARGSUSED*/ |
---|
| 1316 | /* Flush any buffers to disk. May be a no-op on if I/O is unbuffered. |
---|
| 1317 | */ |
---|
| 1318 | static int |
---|
| 1319 | ncio_spx_sync(ncio *const nciop) |
---|
| 1320 | { |
---|
| 1321 | /* NOOP */ |
---|
| 1322 | return ENOERR; |
---|
| 1323 | } |
---|
| 1324 | |
---|
| 1325 | static void |
---|
| 1326 | ncio_spx_freepvt(void *const pvt) |
---|
| 1327 | { |
---|
| 1328 | ncio_spx *const pxp = (ncio_spx *)pvt; |
---|
| 1329 | if(pxp == NULL) |
---|
| 1330 | return; |
---|
| 1331 | |
---|
| 1332 | if(pxp->bf_base != NULL) |
---|
| 1333 | { |
---|
| 1334 | free(pxp->bf_base); |
---|
| 1335 | pxp->bf_base = NULL; |
---|
| 1336 | pxp->bf_offset = OFF_NONE; |
---|
| 1337 | pxp->bf_extent = 0; |
---|
| 1338 | pxp->bf_cnt = 0; |
---|
| 1339 | } |
---|
| 1340 | } |
---|
| 1341 | |
---|
| 1342 | |
---|
| 1343 | /* This does the second half of the ncio_spx struct initialization for |
---|
| 1344 | POSIX systems, with NC_SHARE on. |
---|
| 1345 | |
---|
| 1346 | nciop - pointer to ncio struct for this file. File has been opened. |
---|
| 1347 | sizehintp - pointer to a size which will be rounded up to the |
---|
| 1348 | nearest 8-byt boundary and then used as the max size "chunk" (or |
---|
| 1349 | page) to read from the file. |
---|
| 1350 | */ |
---|
| 1351 | static int |
---|
| 1352 | ncio_spx_init2(ncio *const nciop, const size_t *const sizehintp) |
---|
| 1353 | { |
---|
| 1354 | ncio_spx *const pxp = (ncio_spx *)nciop->pvt; |
---|
| 1355 | |
---|
| 1356 | assert(nciop->fd >= 0); |
---|
| 1357 | |
---|
| 1358 | pxp->bf_extent = *sizehintp; |
---|
| 1359 | |
---|
| 1360 | assert(pxp->bf_base == NULL); |
---|
| 1361 | |
---|
| 1362 | /* this is separate allocation because it may grow */ |
---|
| 1363 | pxp->bf_base = malloc(pxp->bf_extent); |
---|
| 1364 | if(pxp->bf_base == NULL) |
---|
| 1365 | { |
---|
| 1366 | pxp->bf_extent = 0; |
---|
| 1367 | return ENOMEM; |
---|
| 1368 | } |
---|
| 1369 | /* else */ |
---|
| 1370 | return ENOERR; |
---|
| 1371 | } |
---|
| 1372 | |
---|
| 1373 | |
---|
| 1374 | /* First half of init for ncio_spx struct, setting the rel, get, move, |
---|
| 1375 | snyc, and free function pointers to the NC_SHARE versions of these |
---|
| 1376 | functions (i.e. the ncio_spx_* functions). |
---|
| 1377 | */ |
---|
| 1378 | static void |
---|
| 1379 | ncio_spx_init(ncio *const nciop) |
---|
| 1380 | { |
---|
| 1381 | ncio_spx *const pxp = (ncio_spx *)nciop->pvt; |
---|
| 1382 | |
---|
| 1383 | *((ncio_relfunc **)&nciop->rel) = ncio_spx_rel; /* cast away const */ |
---|
| 1384 | *((ncio_getfunc **)&nciop->get) = ncio_spx_get; /* cast away const */ |
---|
| 1385 | *((ncio_movefunc **)&nciop->move) = ncio_spx_move; /* cast away const */ |
---|
| 1386 | *((ncio_syncfunc **)&nciop->sync) = ncio_spx_sync; /* cast away const */ |
---|
| 1387 | /* shared with _px_ */ |
---|
| 1388 | *((ncio_filesizefunc **)&nciop->filesize) = ncio_px_filesize; /* cast away const */ |
---|
| 1389 | *((ncio_pad_lengthfunc **)&nciop->pad_length) = ncio_px_pad_length; /* cast away const */ |
---|
| 1390 | *((ncio_closefunc **)&nciop->close) = ncio_spx_close; /* cast away const */ |
---|
| 1391 | |
---|
| 1392 | pxp->pos = -1; |
---|
| 1393 | pxp->bf_offset = OFF_NONE; |
---|
| 1394 | pxp->bf_extent = 0; |
---|
| 1395 | pxp->bf_cnt = 0; |
---|
| 1396 | pxp->bf_base = NULL; |
---|
| 1397 | } |
---|
| 1398 | |
---|
| 1399 | |
---|
| 1400 | /* */ |
---|
| 1401 | |
---|
| 1402 | /* This will call whatever free function is attached to the free |
---|
| 1403 | function pointer in ncio. It's called from ncio_close, and from |
---|
| 1404 | ncio_open and ncio_create when an error occurs that the file |
---|
| 1405 | metadata must be freed. |
---|
| 1406 | */ |
---|
| 1407 | static void |
---|
| 1408 | ncio_px_free(ncio *nciop) |
---|
| 1409 | { |
---|
| 1410 | if(nciop == NULL) |
---|
| 1411 | return; |
---|
| 1412 | if(nciop->pvt != NULL) |
---|
| 1413 | ncio_px_freepvt(nciop->pvt); |
---|
| 1414 | free(nciop); |
---|
| 1415 | } |
---|
| 1416 | |
---|
| 1417 | static void |
---|
| 1418 | ncio_spx_free(ncio *nciop) |
---|
| 1419 | { |
---|
| 1420 | if(nciop == NULL) |
---|
| 1421 | return; |
---|
| 1422 | if(nciop->pvt != NULL) |
---|
| 1423 | ncio_spx_freepvt(nciop->pvt); |
---|
| 1424 | free(nciop); |
---|
| 1425 | } |
---|
| 1426 | |
---|
| 1427 | |
---|
| 1428 | /* Create a new ncio struct to hold info about the file. This will |
---|
| 1429 | create and init the ncio_px or ncio_spx struct (the latter if |
---|
| 1430 | NC_SHARE is used.) |
---|
| 1431 | */ |
---|
| 1432 | static ncio * |
---|
| 1433 | ncio_px_new(const char *path, int ioflags) |
---|
| 1434 | { |
---|
| 1435 | size_t sz_ncio = M_RNDUP(sizeof(ncio)); |
---|
| 1436 | size_t sz_path = M_RNDUP(strlen(path) +1); |
---|
| 1437 | size_t sz_ncio_pvt; |
---|
| 1438 | ncio *nciop; |
---|
| 1439 | |
---|
| 1440 | #if ALWAYS_NC_SHARE /* DEBUG */ |
---|
| 1441 | fSet(ioflags, NC_SHARE); |
---|
| 1442 | #endif |
---|
| 1443 | |
---|
| 1444 | if(fIsSet(ioflags, NC_SHARE)) |
---|
| 1445 | sz_ncio_pvt = sizeof(ncio_spx); |
---|
| 1446 | else |
---|
| 1447 | sz_ncio_pvt = sizeof(ncio_px); |
---|
| 1448 | |
---|
| 1449 | nciop = (ncio *) malloc(sz_ncio + sz_path + sz_ncio_pvt); |
---|
| 1450 | if(nciop == NULL) |
---|
| 1451 | return NULL; |
---|
| 1452 | |
---|
| 1453 | nciop->ioflags = ioflags; |
---|
| 1454 | *((int *)&nciop->fd) = -1; /* cast away const */ |
---|
| 1455 | |
---|
| 1456 | nciop->path = (char *) ((char *)nciop + sz_ncio); |
---|
| 1457 | (void) strcpy((char *)nciop->path, path); /* cast away const */ |
---|
| 1458 | |
---|
| 1459 | /* cast away const */ |
---|
| 1460 | *((void **)&nciop->pvt) = (void *)(nciop->path + sz_path); |
---|
| 1461 | |
---|
| 1462 | if(fIsSet(ioflags, NC_SHARE)) |
---|
| 1463 | ncio_spx_init(nciop); |
---|
| 1464 | else |
---|
| 1465 | ncio_px_init(nciop); |
---|
| 1466 | |
---|
| 1467 | return nciop; |
---|
| 1468 | } |
---|
| 1469 | |
---|
| 1470 | |
---|
| 1471 | /* Public below this point */ |
---|
| 1472 | #ifndef NCIO_MINBLOCKSIZE |
---|
| 1473 | #define NCIO_MINBLOCKSIZE 256 |
---|
| 1474 | #endif |
---|
| 1475 | #ifndef NCIO_MAXBLOCKSIZE |
---|
| 1476 | #define NCIO_MAXBLOCKSIZE 268435456 /* sanity check, about X_SIZE_T_MAX/8 */ |
---|
| 1477 | #endif |
---|
| 1478 | |
---|
| 1479 | #ifdef S_IRUSR |
---|
| 1480 | #define NC_DEFAULT_CREAT_MODE \ |
---|
| 1481 | (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH) /* 0666 */ |
---|
| 1482 | |
---|
| 1483 | #else |
---|
| 1484 | #define NC_DEFAULT_CREAT_MODE 0666 |
---|
| 1485 | #endif |
---|
| 1486 | |
---|
| 1487 | /* Create a file, and the ncio struct to go with it. This funtion is |
---|
| 1488 | only called from nc__create_mp. |
---|
| 1489 | |
---|
| 1490 | path - path of file to create. |
---|
| 1491 | ioflags - flags from nc_create |
---|
| 1492 | initialsz - From the netcdf man page: "The argument |
---|
| 1493 | Iinitialsize sets the initial size of the file at creation time." |
---|
| 1494 | igeto - |
---|
| 1495 | igetsz - |
---|
| 1496 | sizehintp - this eventually goes into pxp->blksz and is the size of |
---|
| 1497 | a page of data for buffered reads and writes. |
---|
| 1498 | nciopp - pointer to a pointer that will get location of newly |
---|
| 1499 | created and inited ncio struct. |
---|
| 1500 | igetvpp - pointer to pointer which will get the location of ? |
---|
| 1501 | */ |
---|
| 1502 | int |
---|
| 1503 | posixio_create(const char *path, int ioflags, |
---|
| 1504 | size_t initialsz, |
---|
| 1505 | off_t igeto, size_t igetsz, size_t *sizehintp, |
---|
| 1506 | ncio **nciopp, void **const igetvpp) |
---|
| 1507 | { |
---|
| 1508 | ncio *nciop; |
---|
| 1509 | int oflags = (O_RDWR|O_CREAT); |
---|
| 1510 | int fd; |
---|
| 1511 | int status; |
---|
| 1512 | |
---|
| 1513 | if(initialsz < (size_t)igeto + igetsz) |
---|
| 1514 | initialsz = (size_t)igeto + igetsz; |
---|
| 1515 | |
---|
| 1516 | fSet(ioflags, NC_WRITE); |
---|
| 1517 | |
---|
| 1518 | if(path == NULL || *path == 0) |
---|
| 1519 | return EINVAL; |
---|
| 1520 | |
---|
| 1521 | nciop = ncio_px_new(path, ioflags); |
---|
| 1522 | if(nciop == NULL) |
---|
| 1523 | return ENOMEM; |
---|
| 1524 | |
---|
| 1525 | if(fIsSet(ioflags, NC_NOCLOBBER)) |
---|
| 1526 | fSet(oflags, O_EXCL); |
---|
| 1527 | else |
---|
| 1528 | fSet(oflags, O_TRUNC); |
---|
| 1529 | #ifdef O_BINARY |
---|
| 1530 | fSet(oflags, O_BINARY); |
---|
| 1531 | #endif |
---|
| 1532 | #ifdef vms |
---|
| 1533 | fd = open(path, oflags, NC_DEFAULT_CREAT_MODE, "ctx=stm"); |
---|
| 1534 | #else |
---|
| 1535 | /* Should we mess with the mode based on NC_SHARE ?? */ |
---|
| 1536 | fd = open(path, oflags, NC_DEFAULT_CREAT_MODE); |
---|
| 1537 | #endif |
---|
| 1538 | #if 0 |
---|
| 1539 | (void) fprintf(stderr, "ncio_create(): path=\"%s\"\n", path); |
---|
| 1540 | (void) fprintf(stderr, "ncio_create(): oflags=0x%x\n", oflags); |
---|
| 1541 | #endif |
---|
| 1542 | if(fd < 0) |
---|
| 1543 | { |
---|
| 1544 | status = errno; |
---|
| 1545 | goto unwind_new; |
---|
| 1546 | } |
---|
| 1547 | *((int *)&nciop->fd) = fd; /* cast away const */ |
---|
| 1548 | |
---|
| 1549 | if(*sizehintp < NCIO_MINBLOCKSIZE) |
---|
| 1550 | { |
---|
| 1551 | /* Use default */ |
---|
| 1552 | *sizehintp = blksize(fd); |
---|
| 1553 | } |
---|
| 1554 | else if(*sizehintp >= NCIO_MAXBLOCKSIZE) |
---|
| 1555 | { |
---|
| 1556 | /* Use maximum allowed value */ |
---|
| 1557 | *sizehintp = NCIO_MAXBLOCKSIZE; |
---|
| 1558 | } |
---|
| 1559 | else |
---|
| 1560 | { |
---|
| 1561 | *sizehintp = M_RNDUP(*sizehintp); |
---|
| 1562 | } |
---|
| 1563 | |
---|
| 1564 | if(fIsSet(nciop->ioflags, NC_SHARE)) |
---|
| 1565 | status = ncio_spx_init2(nciop, sizehintp); |
---|
| 1566 | else |
---|
| 1567 | status = ncio_px_init2(nciop, sizehintp, 1); |
---|
| 1568 | |
---|
| 1569 | if(status != ENOERR) |
---|
| 1570 | goto unwind_open; |
---|
| 1571 | |
---|
| 1572 | if(initialsz != 0) |
---|
| 1573 | { |
---|
| 1574 | status = fgrow(fd, (off_t)initialsz); |
---|
| 1575 | if(status != ENOERR) |
---|
| 1576 | goto unwind_open; |
---|
| 1577 | } |
---|
| 1578 | |
---|
| 1579 | if(igetsz != 0) |
---|
| 1580 | { |
---|
| 1581 | status = nciop->get(nciop, |
---|
| 1582 | igeto, igetsz, |
---|
| 1583 | RGN_WRITE, |
---|
| 1584 | igetvpp); |
---|
| 1585 | if(status != ENOERR) |
---|
| 1586 | goto unwind_open; |
---|
| 1587 | } |
---|
| 1588 | |
---|
| 1589 | *nciopp = nciop; |
---|
| 1590 | return ENOERR; |
---|
| 1591 | |
---|
| 1592 | unwind_open: |
---|
| 1593 | (void) close(fd); |
---|
| 1594 | /* ?? unlink */ |
---|
| 1595 | /*FALLTHRU*/ |
---|
| 1596 | unwind_new: |
---|
| 1597 | ncio_close(nciop,!fIsSet(ioflags, NC_NOCLOBBER)); |
---|
| 1598 | return status; |
---|
| 1599 | } |
---|
| 1600 | |
---|
| 1601 | |
---|
| 1602 | /* This function opens the data file. It is only called from nc.c, |
---|
| 1603 | from nc__open_mp and nc_delete_mp. |
---|
| 1604 | |
---|
| 1605 | path - path of data file. |
---|
| 1606 | |
---|
| 1607 | ioflags - flags passed into nc_open. |
---|
| 1608 | |
---|
| 1609 | igeto - looks like this function can do an initial page get, and |
---|
| 1610 | igeto is going to be the offset for that. But it appears to be |
---|
| 1611 | unused |
---|
| 1612 | |
---|
| 1613 | igetsz - the size in bytes of initial page get (a.k.a. extent). Not |
---|
| 1614 | ever used in the library. |
---|
| 1615 | |
---|
| 1616 | sizehintp - pointer to sizehint parameter from nc__open or |
---|
| 1617 | nc__create. This is used to set pxp->blksz. |
---|
| 1618 | |
---|
| 1619 | Here's what the man page has to say: |
---|
| 1620 | |
---|
| 1621 | "The argument referenced by chunksize controls a space versus time |
---|
| 1622 | tradeoff, memory allocated in the netcdf library versus number of |
---|
| 1623 | system calls. |
---|
| 1624 | |
---|
| 1625 | Because of internal requirements, the value may not be set to |
---|
| 1626 | exactly the value requested. The actual value chosen is returned by reference. |
---|
| 1627 | |
---|
| 1628 | Using the value NC_SIZEHINT_DEFAULT causes the library to choose a |
---|
| 1629 | default. How the system choses the default depends on the |
---|
| 1630 | system. On many systems, the "preferred I/O block size" is |
---|
| 1631 | available from the stat() system call, struct stat member |
---|
| 1632 | st_blksize. If this is available it is used. Lacking that, twice |
---|
| 1633 | the system pagesize is used. Lacking a call to discover the system |
---|
| 1634 | pagesize, we just set default chunksize to 8192. |
---|
| 1635 | |
---|
| 1636 | The chunksize is a property of a given open netcdf descriptor ncid, |
---|
| 1637 | it is not a persistent property of the netcdf dataset." |
---|
| 1638 | |
---|
| 1639 | nciopp - pointer to pointer that will get address of newly created |
---|
| 1640 | and inited ncio struct. |
---|
| 1641 | |
---|
| 1642 | igetvpp - handle to pass back pointer to data from inital page |
---|
| 1643 | read, if this were ever used, which it isn't. |
---|
| 1644 | */ |
---|
| 1645 | int |
---|
| 1646 | posixio_open(const char *path, |
---|
| 1647 | int ioflags, |
---|
| 1648 | off_t igeto, size_t igetsz, size_t *sizehintp, |
---|
| 1649 | ncio **nciopp, void **const igetvpp) |
---|
| 1650 | { |
---|
| 1651 | ncio *nciop; |
---|
| 1652 | int oflags = fIsSet(ioflags, NC_WRITE) ? O_RDWR : O_RDONLY; |
---|
| 1653 | int fd; |
---|
| 1654 | int status; |
---|
| 1655 | |
---|
| 1656 | if(path == NULL || *path == 0) |
---|
| 1657 | return EINVAL; |
---|
| 1658 | |
---|
| 1659 | nciop = ncio_px_new(path, ioflags); |
---|
| 1660 | if(nciop == NULL) |
---|
| 1661 | return ENOMEM; |
---|
| 1662 | |
---|
| 1663 | #ifdef O_BINARY |
---|
| 1664 | fSet(oflags, O_BINARY); |
---|
| 1665 | #endif |
---|
| 1666 | #ifdef vms |
---|
| 1667 | fd = open(path, oflags, 0, "ctx=stm"); |
---|
| 1668 | #else |
---|
| 1669 | fd = open(path, oflags, 0); |
---|
| 1670 | #endif |
---|
| 1671 | if(fd < 0) |
---|
| 1672 | { |
---|
| 1673 | status = errno; |
---|
| 1674 | goto unwind_new; |
---|
| 1675 | } |
---|
| 1676 | *((int *)&nciop->fd) = fd; /* cast away const */ |
---|
| 1677 | |
---|
| 1678 | if(*sizehintp < NCIO_MINBLOCKSIZE) |
---|
| 1679 | { |
---|
| 1680 | /* Use default */ |
---|
| 1681 | *sizehintp = blksize(fd); |
---|
| 1682 | } |
---|
| 1683 | else if(*sizehintp >= NCIO_MAXBLOCKSIZE) |
---|
| 1684 | { |
---|
| 1685 | /* Use maximum allowed value */ |
---|
| 1686 | *sizehintp = NCIO_MAXBLOCKSIZE; |
---|
| 1687 | } |
---|
| 1688 | else |
---|
| 1689 | { |
---|
| 1690 | *sizehintp = M_RNDUP(*sizehintp); |
---|
| 1691 | } |
---|
| 1692 | |
---|
| 1693 | if(fIsSet(nciop->ioflags, NC_SHARE)) |
---|
| 1694 | status = ncio_spx_init2(nciop, sizehintp); |
---|
| 1695 | else |
---|
| 1696 | status = ncio_px_init2(nciop, sizehintp, 0); |
---|
| 1697 | |
---|
| 1698 | if(status != ENOERR) |
---|
| 1699 | goto unwind_open; |
---|
| 1700 | |
---|
| 1701 | if(igetsz != 0) |
---|
| 1702 | { |
---|
| 1703 | status = nciop->get(nciop, |
---|
| 1704 | igeto, igetsz, |
---|
| 1705 | 0, |
---|
| 1706 | igetvpp); |
---|
| 1707 | if(status != ENOERR) |
---|
| 1708 | goto unwind_open; |
---|
| 1709 | } |
---|
| 1710 | |
---|
| 1711 | *nciopp = nciop; |
---|
| 1712 | return ENOERR; |
---|
| 1713 | |
---|
| 1714 | unwind_open: |
---|
| 1715 | (void) close(fd); |
---|
| 1716 | /*FALLTHRU*/ |
---|
| 1717 | unwind_new: |
---|
| 1718 | ncio_close(nciop,0); |
---|
| 1719 | return status; |
---|
| 1720 | } |
---|
| 1721 | |
---|
| 1722 | /* |
---|
| 1723 | * Get file size in bytes. |
---|
| 1724 | */ |
---|
| 1725 | static int |
---|
| 1726 | ncio_px_filesize(ncio *nciop, off_t *filesizep) |
---|
| 1727 | { |
---|
| 1728 | struct stat sb; |
---|
| 1729 | |
---|
| 1730 | assert(nciop != NULL); |
---|
| 1731 | if (fstat(nciop->fd, &sb) < 0) |
---|
| 1732 | return errno; |
---|
| 1733 | *filesizep = sb.st_size; |
---|
| 1734 | return ENOERR; |
---|
| 1735 | } |
---|
| 1736 | |
---|
| 1737 | /* |
---|
| 1738 | * Sync any changes to disk, then truncate or extend file so its size |
---|
| 1739 | * is length. This is only intended to be called before close, if the |
---|
| 1740 | * file is open for writing and the actual size does not match the |
---|
| 1741 | * calculated size, perhaps as the result of having been previously |
---|
| 1742 | * written in NOFILL mode. |
---|
| 1743 | */ |
---|
| 1744 | static int |
---|
| 1745 | ncio_px_pad_length(ncio *nciop, off_t length) |
---|
| 1746 | { |
---|
| 1747 | int status = ENOERR; |
---|
| 1748 | |
---|
| 1749 | if(nciop == NULL) |
---|
| 1750 | return EINVAL; |
---|
| 1751 | |
---|
| 1752 | if(!fIsSet(nciop->ioflags, NC_WRITE)) |
---|
| 1753 | return EPERM; /* attempt to write readonly file */ |
---|
| 1754 | |
---|
| 1755 | status = nciop->sync(nciop); |
---|
| 1756 | if(status != ENOERR) |
---|
| 1757 | return status; |
---|
| 1758 | |
---|
| 1759 | status = fgrow2(nciop->fd, length); |
---|
| 1760 | if(status != ENOERR) |
---|
| 1761 | return status; |
---|
| 1762 | return ENOERR; |
---|
| 1763 | } |
---|
| 1764 | |
---|
| 1765 | |
---|
| 1766 | /* Write out any dirty buffers to disk and |
---|
| 1767 | ensure that next read will get data from disk. |
---|
| 1768 | |
---|
| 1769 | Sync any changes, then close the open file associated with the ncio |
---|
| 1770 | struct, and free its memory. |
---|
| 1771 | |
---|
| 1772 | nciop - pointer to ncio to close. |
---|
| 1773 | |
---|
| 1774 | doUnlink - if true, unlink file |
---|
| 1775 | */ |
---|
| 1776 | static int |
---|
| 1777 | ncio_px_close(ncio *nciop, int doUnlink) |
---|
| 1778 | { |
---|
| 1779 | int status = ENOERR; |
---|
| 1780 | if(nciop == NULL) |
---|
| 1781 | return EINVAL; |
---|
| 1782 | status = nciop->sync(nciop); |
---|
| 1783 | (void) close(nciop->fd); |
---|
| 1784 | if(doUnlink) |
---|
| 1785 | (void) unlink(nciop->path); |
---|
| 1786 | ncio_px_free(nciop); |
---|
| 1787 | return status; |
---|
| 1788 | } |
---|
| 1789 | |
---|
| 1790 | static int |
---|
| 1791 | ncio_spx_close(ncio *nciop, int doUnlink) |
---|
| 1792 | { |
---|
| 1793 | int status = ENOERR; |
---|
| 1794 | if(nciop == NULL) |
---|
| 1795 | return EINVAL; |
---|
| 1796 | status = nciop->sync(nciop); |
---|
| 1797 | (void) close(nciop->fd); |
---|
| 1798 | if(doUnlink) |
---|
| 1799 | (void) unlink(nciop->path); |
---|
| 1800 | ncio_spx_free(nciop); |
---|
| 1801 | return status; |
---|
| 1802 | } |
---|