[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 | |
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| 6 | #include "config.h" |
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| 7 | #include <assert.h> |
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| 8 | #include <stdlib.h> |
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| 9 | #include <errno.h> |
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| 10 | #include <string.h> |
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| 11 | #ifdef _MSC_VER /* Microsoft Compilers */ |
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| 12 | #include <io.h> |
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| 13 | #endif |
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| 14 | #ifdef HAVE_UNISTD_H |
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| 15 | #include <unistd.h> |
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| 16 | #endif |
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| 17 | #ifdef HAVE_FCNTL_H |
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| 18 | #include <fcntl.h> |
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| 19 | #endif |
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| 20 | #include "nc.h" |
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| 21 | |
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| 22 | #undef DEBUG |
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| 23 | |
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| 24 | #ifdef DEBUG |
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| 25 | #include <stdio.h> |
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| 26 | #endif |
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| 27 | |
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| 28 | #include <sys/mman.h> |
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| 29 | |
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| 30 | #ifndef MAP_ANONYMOUS |
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| 31 | # ifdef MAP_ANON |
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| 32 | # define MAP_ANONYMOUS MAP_ANON |
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| 33 | # endif |
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| 34 | #endif |
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| 35 | |
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| 36 | /* !MAP_ANONYMOUS => !HAVE_MMAP */ |
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| 37 | #ifndef MAP_ANONYMOUS |
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| 38 | #error mmap not fully implemented: missing MAP_ANONYMOUS |
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| 39 | #endif |
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| 40 | |
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| 41 | #ifdef HAVE_MMAP |
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| 42 | /* This is conditionalized by __USE_GNU ; why? */ |
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| 43 | extern void *mremap(void*,size_t,size_t,int); |
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| 44 | # ifndef MREMAP_MAYMOVE |
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| 45 | # define MREMAP_MAYMOVE 1 |
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| 46 | # endif |
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| 47 | #endif /*HAVE_MMAP*/ |
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| 48 | |
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| 49 | #ifndef HAVE_SSIZE_T |
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| 50 | #define ssize_t int |
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| 51 | #endif |
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| 52 | |
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| 53 | #ifndef SEEK_SET |
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| 54 | #define SEEK_SET 0 |
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| 55 | #define SEEK_CUR 1 |
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| 56 | #define SEEK_END 2 |
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| 57 | #endif |
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| 58 | |
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| 59 | /* Define the mode flags for create: let umask decide */ |
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| 60 | #define OPENMODE 0666 |
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| 61 | |
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| 62 | #include "ncio.h" |
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| 63 | #include "fbits.h" |
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| 64 | #include "rnd.h" |
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| 65 | |
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| 66 | /* #define INSTRUMENT 1 */ |
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| 67 | #if INSTRUMENT /* debugging */ |
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| 68 | #undef NDEBUG |
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| 69 | #include <stdio.h> |
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| 70 | /*#include "instr.h"*/ |
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| 71 | #endif |
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| 72 | |
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| 73 | #ifndef MMAP_MAXBLOCKSIZE |
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| 74 | #define MMAP_MAXBLOCKSIZE 268435456 /* sanity check, about X_SIZE_T_MAX/8 */ |
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| 75 | #endif |
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| 76 | |
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| 77 | #undef MIN /* system may define MIN somewhere and complain */ |
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| 78 | #define MIN(mm,nn) (((mm) < (nn)) ? (mm) : (nn)) |
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| 79 | |
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| 80 | #if !defined(NDEBUG) && !defined(X_INT_MAX) |
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| 81 | #define X_INT_MAX 2147483647 |
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| 82 | #endif |
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| 83 | |
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| 84 | #if 0 /* !defined(NDEBUG) && !defined(X_ALIGN) */ |
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| 85 | #define X_ALIGN 4 |
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| 86 | #else |
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| 87 | #undef X_ALIGN |
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| 88 | #endif |
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| 89 | |
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| 90 | /* Private data for mmap */ |
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| 91 | |
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| 92 | typedef struct NCMMAPIO { |
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| 93 | int locked; /* => we cannot realloc */ |
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| 94 | int persist; /* => save to a file; triggered by NC_WRITE */ |
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| 95 | char* memory; |
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| 96 | off_t alloc; |
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| 97 | off_t size; |
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| 98 | off_t pos; |
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| 99 | int mapfd; |
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| 100 | } NCMMAPIO; |
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| 101 | |
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| 102 | /* Forward */ |
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| 103 | static int mmapio_rel(ncio *const nciop, off_t offset, int rflags); |
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| 104 | static int mmapio_get(ncio *const nciop, off_t offset, size_t extent, int rflags, void **const vpp); |
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| 105 | static int mmapio_move(ncio *const nciop, off_t to, off_t from, size_t nbytes, int rflags); |
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| 106 | static int mmapio_sync(ncio *const nciop); |
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| 107 | static int mmapio_filesize(ncio* nciop, off_t* filesizep); |
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| 108 | static int mmapio_pad_length(ncio* nciop, off_t length); |
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| 109 | static int mmapio_close(ncio* nciop, int); |
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| 110 | |
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| 111 | /* Mnemonic */ |
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| 112 | #define DOOPEN 1 |
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| 113 | |
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| 114 | static long pagesize = 0; |
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| 115 | |
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| 116 | /* Create a new ncio struct to hold info about the file. */ |
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| 117 | static int |
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| 118 | mmapio_new(const char* path, int ioflags, off_t initialsize, ncio** nciopp, NCMMAPIO** mmapp) |
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| 119 | { |
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| 120 | int status = NC_NOERR; |
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| 121 | ncio* nciop = NULL; |
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| 122 | NCMMAPIO* mmapio = NULL; |
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| 123 | int openfd = -1; |
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| 124 | |
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| 125 | if(pagesize == 0) { |
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| 126 | #if defined HAVE_SYSCONF |
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| 127 | pagesize = sysconf(_SC_PAGE_SIZE); |
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| 128 | #elif defined HAVE_GETPAGESIZE |
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| 129 | pagesize = getpagesize(); |
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| 130 | #else |
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| 131 | pagesize = 4096; /* good guess */ |
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| 132 | #endif |
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| 133 | } |
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| 134 | |
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| 135 | errno = 0; |
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| 136 | |
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| 137 | /* Always force the allocated size to be a multiple of pagesize */ |
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| 138 | if(initialsize == 0) initialsize = pagesize; |
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| 139 | if((initialsize % pagesize) != 0) |
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| 140 | initialsize += (pagesize - (initialsize % pagesize)); |
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| 141 | |
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| 142 | nciop = (ncio* )calloc(1,sizeof(ncio)); |
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| 143 | if(nciop == NULL) {status = NC_ENOMEM; goto fail;} |
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| 144 | |
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| 145 | nciop->ioflags = ioflags; |
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| 146 | *((int*)&nciop->fd) = -1; /* caller will fix */ |
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| 147 | |
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| 148 | *((char**)&nciop->path) = strdup(path); |
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| 149 | if(nciop->path == NULL) {status = NC_ENOMEM; goto fail;} |
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| 150 | |
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| 151 | *((ncio_relfunc**)&nciop->rel) = mmapio_rel; |
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| 152 | *((ncio_getfunc**)&nciop->get) = mmapio_get; |
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| 153 | *((ncio_movefunc**)&nciop->move) = mmapio_move; |
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| 154 | *((ncio_syncfunc**)&nciop->sync) = mmapio_sync; |
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| 155 | *((ncio_filesizefunc**)&nciop->filesize) = mmapio_filesize; |
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| 156 | *((ncio_pad_lengthfunc**)&nciop->pad_length) = mmapio_pad_length; |
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| 157 | *((ncio_closefunc**)&nciop->close) = mmapio_close; |
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| 158 | |
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| 159 | mmapio = (NCMMAPIO*)calloc(1,sizeof(NCMMAPIO)); |
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| 160 | if(mmapio == NULL) {status = NC_ENOMEM; goto fail;} |
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| 161 | *((void* *)&nciop->pvt) = mmapio; |
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| 162 | |
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| 163 | mmapio->alloc = initialsize; |
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| 164 | |
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| 165 | mmapio->memory = NULL; |
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| 166 | mmapio->size = 0; |
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| 167 | mmapio->pos = 0; |
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| 168 | mmapio->persist = fIsSet(ioflags,NC_WRITE); |
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| 169 | |
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| 170 | /* See if ok to use mmap */ |
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| 171 | if(sizeof(void*) < 8 && fIsSet(ioflags,NC_64BIT_OFFSET)) |
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| 172 | return NC_DISKLESS; /* cannot support */ |
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| 173 | mmapio->mapfd = -1; |
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| 174 | |
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| 175 | if(nciopp) *nciopp = nciop; |
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| 176 | if(mmapp) *mmapp = mmapio; |
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| 177 | |
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| 178 | done: |
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| 179 | if(openfd >= 0) close(openfd); |
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| 180 | return status; |
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| 181 | |
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| 182 | fail: |
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| 183 | if(nciop != NULL) { |
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| 184 | if(nciop->path != NULL) free((char*)nciop->path); |
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| 185 | } |
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| 186 | goto done; |
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| 187 | } |
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| 188 | |
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| 189 | /* Create a file, and the ncio struct to go with it. This function is |
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| 190 | only called from nc__create_mp. |
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| 191 | |
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| 192 | path - path of file to create. |
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| 193 | ioflags - flags from nc_create |
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| 194 | initialsz - From the netcdf man page: "The argument |
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| 195 | Iinitialsize sets the initial size of the file at creation time." |
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| 196 | igeto - |
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| 197 | igetsz - |
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| 198 | sizehintp - the size of a page of data for buffered reads and writes. |
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| 199 | nciopp - pointer to a pointer that will get location of newly |
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| 200 | created and inited ncio struct. |
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| 201 | mempp - pointer to pointer to the initial memory read. |
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| 202 | */ |
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| 203 | int |
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| 204 | mmapio_create(const char* path, int ioflags, |
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| 205 | size_t initialsz, |
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| 206 | off_t igeto, size_t igetsz, size_t* sizehintp, |
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| 207 | ncio* *nciopp, void** const mempp) |
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| 208 | { |
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| 209 | ncio* nciop; |
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| 210 | int fd; |
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| 211 | int status; |
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| 212 | NCMMAPIO* mmapio = NULL; |
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| 213 | int persist = (ioflags & NC_WRITE?1:0); |
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| 214 | int oflags; |
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| 215 | |
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| 216 | if(path == NULL ||* path == 0) |
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| 217 | return NC_EINVAL; |
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| 218 | |
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| 219 | /* For diskless open has, the file must be classic version 1 or 2.*/ |
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| 220 | if(fIsSet(ioflags,NC_NETCDF4)) |
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| 221 | return NC_EDISKLESS; /* violates constraints */ |
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| 222 | |
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| 223 | status = mmapio_new(path, ioflags, initialsz, &nciop, &mmapio); |
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| 224 | if(status != NC_NOERR) |
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| 225 | return status; |
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| 226 | mmapio->size = 0; |
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| 227 | |
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| 228 | if(!persist) { |
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| 229 | mmapio->mapfd = -1; |
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| 230 | mmapio->memory = (char*)mmap(NULL,mmapio->alloc, |
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| 231 | PROT_READ|PROT_WRITE, |
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| 232 | MAP_PRIVATE|MAP_ANONYMOUS, |
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| 233 | mmapio->mapfd,0); |
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| 234 | {mmapio->memory[0] = 0;} /* test writing of the mmap'd memory */ |
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| 235 | } else { /*persist */ |
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| 236 | /* Open the file, but make sure we can write it if needed */ |
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| 237 | oflags = (persist ? O_RDWR : O_RDONLY); |
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| 238 | #ifdef O_BINARY |
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| 239 | fSet(oflags, O_BINARY); |
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| 240 | #endif |
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| 241 | oflags |= (O_CREAT|O_TRUNC); |
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| 242 | if(fIsSet(ioflags,NC_NOCLOBBER)) |
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| 243 | oflags |= O_EXCL; |
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| 244 | #ifdef vms |
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| 245 | fd = open(path, oflags, 0, "ctx=stm"); |
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| 246 | #else |
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| 247 | fd = open(path, oflags, OPENMODE); |
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| 248 | #endif |
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| 249 | if(fd < 0) {status = errno; goto unwind_open;} |
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| 250 | mmapio->mapfd = fd; |
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| 251 | |
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| 252 | { /* Cause the output file to have enough allocated space */ |
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| 253 | lseek(fd,mmapio->alloc-1,SEEK_SET); /* cause file to appear */ |
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| 254 | write(fd,"",mmapio->alloc); |
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| 255 | lseek(fd,0,SEEK_SET); /* rewind */ |
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| 256 | } |
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| 257 | mmapio->memory = (char*)mmap(NULL,mmapio->alloc, |
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| 258 | PROT_READ|PROT_WRITE, |
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| 259 | MAP_SHARED, |
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| 260 | mmapio->mapfd,0); |
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| 261 | if(mmapio->memory == NULL) { |
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| 262 | return NC_EDISKLESS; |
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| 263 | } |
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| 264 | } /*!persist*/ |
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| 265 | |
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| 266 | #ifdef DEBUG |
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| 267 | fprintf(stderr,"mmap_create: initial memory: %lu/%lu\n",(unsigned long)mmapio->memory,(unsigned long)mmapio->alloc); |
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| 268 | #endif |
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| 269 | |
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| 270 | fd = nc__pseudofd(); |
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| 271 | *((int* )&nciop->fd) = fd; |
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| 272 | |
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| 273 | fSet(nciop->ioflags, NC_WRITE); |
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| 274 | |
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| 275 | if(igetsz != 0) |
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| 276 | { |
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| 277 | status = nciop->get(nciop, |
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| 278 | igeto, igetsz, |
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| 279 | RGN_WRITE, |
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| 280 | mempp); |
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| 281 | if(status != NC_NOERR) |
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| 282 | goto unwind_open; |
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| 283 | } |
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| 284 | |
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| 285 | /* Pick a default sizehint */ |
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| 286 | if(sizehintp) *sizehintp = pagesize; |
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| 287 | |
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| 288 | *nciopp = nciop; |
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| 289 | return NC_NOERR; |
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| 290 | |
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| 291 | unwind_open: |
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| 292 | mmapio_close(nciop,1); |
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| 293 | return status; |
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| 294 | } |
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| 295 | |
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| 296 | /* This function opens the data file. It is only called from nc.c, |
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| 297 | from nc__open_mp and nc_delete_mp. |
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| 298 | |
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| 299 | path - path of data file. |
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| 300 | ioflags - flags passed into nc_open. |
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| 301 | igeto - looks like this function can do an initial page get, and |
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| 302 | igeto is going to be the offset for that. But it appears to be |
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| 303 | unused |
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| 304 | igetsz - the size in bytes of initial page get (a.k.a. extent). Not |
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| 305 | ever used in the library. |
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| 306 | sizehintp - the size of a page of data for buffered reads and writes. |
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| 307 | nciopp - pointer to pointer that will get address of newly created |
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| 308 | and inited ncio struct. |
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| 309 | mempp - pointer to pointer to the initial memory read. |
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| 310 | */ |
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| 311 | int |
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| 312 | mmapio_open(const char* path, |
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| 313 | int ioflags, |
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| 314 | off_t igeto, size_t igetsz, size_t* sizehintp, |
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| 315 | ncio* *nciopp, void** const mempp) |
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| 316 | { |
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| 317 | ncio* nciop; |
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| 318 | int fd; |
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| 319 | int status; |
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| 320 | int persist = (fIsSet(ioflags,NC_WRITE)?1:0); |
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| 321 | int oflags; |
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| 322 | NCMMAPIO* mmapio = NULL; |
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| 323 | size_t sizehint; |
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| 324 | off_t filesize; |
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| 325 | |
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| 326 | if(path == NULL ||* path == 0) |
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| 327 | return EINVAL; |
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| 328 | |
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| 329 | assert(sizehintp != NULL); |
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| 330 | sizehint = *sizehintp; |
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| 331 | |
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| 332 | /* Open the file, but make sure we can write it if needed */ |
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| 333 | oflags = (persist ? O_RDWR : O_RDONLY); |
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| 334 | #ifdef O_BINARY |
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| 335 | fSet(oflags, O_BINARY); |
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| 336 | #endif |
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| 337 | oflags |= O_EXCL; |
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| 338 | #ifdef vms |
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| 339 | fd = open(path, oflags, 0, "ctx=stm"); |
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| 340 | #else |
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| 341 | fd = open(path, oflags, OPENMODE); |
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| 342 | #endif |
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| 343 | if(fd < 0) {status = errno; goto unwind_open;} |
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| 344 | |
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| 345 | /* get current filesize = max(|file|,initialize)*/ |
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| 346 | filesize = lseek(fd,0,SEEK_END); |
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| 347 | if(filesize < 0) {status = errno; goto unwind_open;} |
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| 348 | /* move pointer back to beginning of file */ |
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| 349 | (void)lseek(fd,0,SEEK_SET); |
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| 350 | if(filesize < (off_t)sizehint) |
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| 351 | filesize = (off_t)sizehint; |
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| 352 | |
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| 353 | status = mmapio_new(path, ioflags, filesize, &nciop, &mmapio); |
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| 354 | if(status != NC_NOERR) |
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| 355 | return status; |
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| 356 | mmapio->size = filesize; |
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| 357 | |
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| 358 | mmapio->mapfd = fd; |
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| 359 | mmapio->memory = (char*)mmap(NULL,mmapio->alloc, |
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| 360 | persist?(PROT_READ|PROT_WRITE):(PROT_READ), |
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| 361 | MAP_SHARED, |
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| 362 | mmapio->mapfd,0); |
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| 363 | #ifdef DEBUG |
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| 364 | fprintf(stderr,"mmapio_open: initial memory: %lu/%lu\n",(unsigned long)mmapio->memory,(unsigned long)mmapio->alloc); |
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| 365 | #endif |
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| 366 | |
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| 367 | /* Use half the filesize as the blocksize */ |
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| 368 | sizehint = filesize/2; |
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| 369 | |
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| 370 | fd = nc__pseudofd(); |
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| 371 | *((int* )&nciop->fd) = fd; |
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| 372 | |
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| 373 | if(igetsz != 0) |
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| 374 | { |
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| 375 | status = nciop->get(nciop, |
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| 376 | igeto, igetsz, |
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| 377 | 0, |
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| 378 | mempp); |
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| 379 | if(status != NC_NOERR) |
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| 380 | goto unwind_open; |
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| 381 | } |
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| 382 | |
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| 383 | *sizehintp = sizehint; |
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| 384 | *nciopp = nciop; |
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| 385 | return NC_NOERR; |
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| 386 | |
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| 387 | unwind_open: |
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| 388 | mmapio_close(nciop,0); |
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| 389 | return status; |
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| 390 | } |
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| 391 | |
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| 392 | |
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| 393 | /* |
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| 394 | * Get file size in bytes. |
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| 395 | */ |
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| 396 | static int |
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| 397 | mmapio_filesize(ncio* nciop, off_t* filesizep) |
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| 398 | { |
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| 399 | NCMMAPIO* mmapio; |
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| 400 | if(nciop == NULL || nciop->pvt == NULL) return NC_EINVAL; |
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| 401 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 402 | if(filesizep != NULL) *filesizep = mmapio->size; |
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| 403 | return NC_NOERR; |
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| 404 | } |
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| 405 | |
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| 406 | /* |
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| 407 | * Sync any changes to disk, then truncate or extend file so its size |
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| 408 | * is length. This is only intended to be called before close, if the |
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| 409 | * file is open for writing and the actual size does not match the |
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| 410 | * calculated size, perhaps as the result of having been previously |
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| 411 | * written in NOFILL mode. |
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| 412 | */ |
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| 413 | static int |
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| 414 | mmapio_pad_length(ncio* nciop, off_t length) |
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| 415 | { |
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| 416 | NCMMAPIO* mmapio; |
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| 417 | if(nciop == NULL || nciop->pvt == NULL) return NC_EINVAL; |
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| 418 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 419 | |
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| 420 | if(!fIsSet(nciop->ioflags, NC_WRITE)) |
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| 421 | return EPERM; /* attempt to write readonly file*/ |
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| 422 | |
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| 423 | if(mmapio->locked > 0) |
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| 424 | return NC_EDISKLESS; |
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| 425 | |
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| 426 | if(length > mmapio->alloc) { |
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| 427 | /* Realloc the allocated memory to a multiple of the pagesize*/ |
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| 428 | off_t newsize = length; |
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| 429 | void* newmem = NULL; |
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| 430 | /* Round to a multiple of pagesize */ |
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| 431 | if((newsize % pagesize) != 0) |
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| 432 | newsize += (pagesize - (newsize % pagesize)); |
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| 433 | |
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| 434 | /* Force file size to be properly extended */ |
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| 435 | { /* Cause the output file to have enough allocated space */ |
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| 436 | off_t pos = lseek(mmapio->mapfd,0,SEEK_CUR); /* save current position*/ |
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| 437 | /* cause file to be extended in size */ |
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| 438 | lseek(mmapio->mapfd,newsize-1,SEEK_SET); |
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| 439 | write(mmapio->mapfd,"",mmapio->alloc); |
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| 440 | lseek(mmapio->mapfd,pos,SEEK_SET); /* reset position */ |
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| 441 | } |
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| 442 | |
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| 443 | newmem = (char*)mremap(mmapio->memory,mmapio->alloc,newsize,MREMAP_MAYMOVE); |
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| 444 | if(newmem == NULL) return NC_ENOMEM; |
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| 445 | |
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| 446 | #ifdef DEBUG |
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| 447 | fprintf(stderr,"realloc: %lu/%lu -> %lu/%lu\n", |
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| 448 | (unsigned long)mmapio->memory,(unsigned long)mmapio->alloc, |
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| 449 | (unsigned long)newmem,(unsigned long)newsize); |
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| 450 | #endif |
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| 451 | mmapio->memory = newmem; |
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| 452 | mmapio->alloc = newsize; |
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| 453 | } |
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| 454 | mmapio->size = length; |
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| 455 | return NC_NOERR; |
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| 456 | } |
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| 457 | |
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| 458 | /* Write out any dirty buffers to disk and |
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| 459 | ensure that next read will get data from disk. |
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| 460 | Sync any changes, then close the open file associated with the ncio |
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| 461 | struct, and free its memory. |
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| 462 | nciop - pointer to ncio to close. |
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| 463 | doUnlink - if true, unlink file |
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| 464 | */ |
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| 465 | |
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| 466 | static int |
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| 467 | mmapio_close(ncio* nciop, int doUnlink) |
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| 468 | { |
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| 469 | int status = NC_NOERR; |
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| 470 | NCMMAPIO* mmapio; |
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| 471 | if(nciop == NULL || nciop->pvt == NULL) return NC_NOERR; |
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| 472 | |
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| 473 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 474 | assert(mmapio != NULL); |
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| 475 | |
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| 476 | /* Since we are using mmap, persisting to a file should be automatic */ |
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| 477 | status = munmap(mmapio->memory,mmapio->alloc); |
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| 478 | mmapio->memory = NULL; /* so we do not try to free it */ |
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| 479 | |
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| 480 | /* Close file if it was open */ |
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| 481 | if(mmapio->mapfd >= 0) |
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| 482 | close(mmapio->mapfd); |
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| 483 | |
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| 484 | /* do cleanup */ |
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| 485 | if(mmapio != NULL) free(mmapio); |
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| 486 | if(nciop->path != NULL) free((char*)nciop->path); |
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| 487 | free(nciop); |
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| 488 | return status; |
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| 489 | } |
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| 490 | |
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| 491 | static int |
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| 492 | guarantee(ncio* nciop, off_t endpoint) |
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| 493 | { |
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| 494 | NCMMAPIO* mmapio = (NCMMAPIO*)nciop->pvt; |
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| 495 | if(endpoint > mmapio->alloc) { |
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| 496 | /* extend the allocated memory and size */ |
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| 497 | int status = mmapio_pad_length(nciop,endpoint); |
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| 498 | if(status != NC_NOERR) return status; |
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| 499 | } |
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| 500 | if(mmapio->size < endpoint) |
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| 501 | mmapio->size = endpoint; |
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| 502 | return NC_NOERR; |
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| 503 | } |
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| 504 | |
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| 505 | /* |
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| 506 | * Request that the region (offset, extent) |
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| 507 | * be made available through *vpp. |
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| 508 | */ |
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| 509 | static int |
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| 510 | mmapio_get(ncio* const nciop, off_t offset, size_t extent, int rflags, void** const vpp) |
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| 511 | { |
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| 512 | int status = NC_NOERR; |
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| 513 | NCMMAPIO* mmapio; |
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| 514 | if(nciop == NULL || nciop->pvt == NULL) return NC_EINVAL; |
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| 515 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 516 | status = guarantee(nciop, offset+extent); |
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| 517 | mmapio->locked++; |
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| 518 | if(status != NC_NOERR) return status; |
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| 519 | if(vpp) *vpp = mmapio->memory+offset; |
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| 520 | return NC_NOERR; |
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| 521 | } |
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| 522 | |
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| 523 | /* |
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| 524 | * Like memmove(), safely move possibly overlapping data. |
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| 525 | */ |
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| 526 | static int |
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| 527 | mmapio_move(ncio* const nciop, off_t to, off_t from, size_t nbytes, int ignored) |
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| 528 | { |
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| 529 | int status = NC_NOERR; |
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| 530 | NCMMAPIO* mmapio; |
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| 531 | |
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| 532 | if(nciop == NULL || nciop->pvt == NULL) return NC_EINVAL; |
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| 533 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 534 | if(from < to) { |
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| 535 | /* extend if "to" is not currently allocated */ |
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| 536 | status = guarantee(nciop,to+nbytes); |
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| 537 | if(status != NC_NOERR) return status; |
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| 538 | } |
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| 539 | /* check for overlap */ |
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| 540 | if((to + nbytes) > from || (from + nbytes) > to) { |
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| 541 | /* Ranges overlap */ |
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| 542 | #ifdef HAVE_MEMMOVE |
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| 543 | memmove((void*)(mmapio->memory+to),(void*)(mmapio->memory+from),nbytes); |
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| 544 | #else |
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| 545 | off_t overlap; |
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| 546 | off_t nbytes1; |
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| 547 | if((from + nbytes) > to) { |
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| 548 | overlap = ((from + nbytes) - to); /* # bytes of overlap */ |
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| 549 | nbytes1 = (nbytes - overlap); /* # bytes of non-overlap */ |
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| 550 | /* move the non-overlapping part */ |
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| 551 | memcpy((void*)(mmapio->memory+(to+overlap)), |
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| 552 | (void*)(mmapio->memory+(from+overlap)), |
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| 553 | nbytes1); |
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| 554 | /* move the overlapping part */ |
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| 555 | memcpy((void*)(mmapio->memory+to), |
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| 556 | (void*)(mmapio->memory+from), |
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| 557 | overlap); |
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| 558 | } else { /*((to + nbytes) > from) */ |
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| 559 | overlap = ((to + nbytes) - from); /* # bytes of overlap */ |
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| 560 | nbytes1 = (nbytes - overlap); /* # bytes of non-overlap */ |
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| 561 | /* move the non-overlapping part */ |
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| 562 | memcpy((void*)(mmapio->memory+to), |
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| 563 | (void*)(mmapio->memory+from), |
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| 564 | nbytes1); |
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| 565 | /* move the overlapping part */ |
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| 566 | memcpy((void*)(mmapio->memory+(to+nbytes1)), |
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| 567 | (void*)(mmapio->memory+(from+nbytes1)), |
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| 568 | overlap); |
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| 569 | } |
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| 570 | #endif |
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| 571 | } else {/* no overlap */ |
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| 572 | memcpy((void*)(mmapio->memory+to),(void*)(mmapio->memory+from),nbytes); |
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| 573 | } |
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| 574 | return status; |
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| 575 | } |
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| 576 | |
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| 577 | static int |
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| 578 | mmapio_rel(ncio* const nciop, off_t offset, int rflags) |
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| 579 | { |
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| 580 | NCMMAPIO* mmapio; |
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| 581 | if(nciop == NULL || nciop->pvt == NULL) return NC_EINVAL; |
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| 582 | mmapio = (NCMMAPIO*)nciop->pvt; |
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| 583 | mmapio->locked--; |
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| 584 | return NC_NOERR; /* do nothing */ |
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| 585 | } |
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| 586 | |
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| 587 | /* |
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| 588 | * Write out any dirty buffers to disk and |
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| 589 | * ensure that next read will get data from disk. |
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| 590 | */ |
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| 591 | static int |
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| 592 | mmapio_sync(ncio* const nciop) |
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| 593 | { |
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| 594 | return NC_NOERR; /* do nothing */ |
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| 595 | } |
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