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Diffstat (limited to 'src/3rdparty/zlib/examples/gzlog.c')
-rw-r--r-- | src/3rdparty/zlib/examples/gzlog.c | 413 |
1 files changed, 0 insertions, 413 deletions
diff --git a/src/3rdparty/zlib/examples/gzlog.c b/src/3rdparty/zlib/examples/gzlog.c deleted file mode 100644 index f71f817..0000000 --- a/src/3rdparty/zlib/examples/gzlog.c +++ /dev/null @@ -1,413 +0,0 @@ -/* - * gzlog.c - * Copyright (C) 2004 Mark Adler - * For conditions of distribution and use, see copyright notice in gzlog.h - * version 1.0, 26 Nov 2004 - * - */ - -#include <string.h> /* memcmp() */ -#include <stdlib.h> /* malloc(), free(), NULL */ -#include <sys/types.h> /* size_t, off_t */ -#include <unistd.h> /* read(), close(), sleep(), ftruncate(), */ - /* lseek() */ -#include <fcntl.h> /* open() */ -#include <sys/file.h> /* flock() */ -#include "zlib.h" /* deflateInit2(), deflate(), deflateEnd() */ - -#include "gzlog.h" /* interface */ -#define local static - -/* log object structure */ -typedef struct { - int id; /* object identifier */ - int fd; /* log file descriptor */ - off_t extra; /* offset of extra "ap" subfield */ - off_t mark_off; /* offset of marked data */ - off_t last_off; /* offset of last block */ - unsigned long crc; /* uncompressed crc */ - unsigned long len; /* uncompressed length (modulo 2^32) */ - unsigned stored; /* length of current stored block */ -} gz_log; - -#define GZLOGID 19334 /* gz_log object identifier */ - -#define LOCK_RETRY 1 /* retry lock once a second */ -#define LOCK_PATIENCE 1200 /* try about twenty minutes before forcing */ - -/* acquire a lock on a file */ -local int lock(int fd) -{ - int patience; - - /* try to lock every LOCK_RETRY seconds for LOCK_PATIENCE seconds */ - patience = LOCK_PATIENCE; - do { - if (flock(fd, LOCK_EX + LOCK_NB) == 0) - return 0; - (void)sleep(LOCK_RETRY); - patience -= LOCK_RETRY; - } while (patience > 0); - - /* we've run out of patience -- give up */ - return -1; -} - -/* release lock */ -local void unlock(int fd) -{ - (void)flock(fd, LOCK_UN); -} - -/* release a log object */ -local void log_clean(gz_log *log) -{ - unlock(log->fd); - (void)close(log->fd); - free(log); -} - -/* read an unsigned long from a byte buffer little-endian */ -local unsigned long make_ulg(unsigned char *buf) -{ - int n; - unsigned long val; - - val = (unsigned long)(*buf++); - for (n = 8; n < 32; n += 8) - val += (unsigned long)(*buf++) << n; - return val; -} - -/* read an off_t from a byte buffer little-endian */ -local off_t make_off(unsigned char *buf) -{ - int n; - off_t val; - - val = (off_t)(*buf++); - for (n = 8; n < 64; n += 8) - val += (off_t)(*buf++) << n; - return val; -} - -/* write an unsigned long little-endian to byte buffer */ -local void dice_ulg(unsigned long val, unsigned char *buf) -{ - int n; - - for (n = 0; n < 4; n++) { - *buf++ = val & 0xff; - val >>= 8; - } -} - -/* write an off_t little-endian to byte buffer */ -local void dice_off(off_t val, unsigned char *buf) -{ - int n; - - for (n = 0; n < 8; n++) { - *buf++ = val & 0xff; - val >>= 8; - } -} - -/* initial, empty gzip file for appending */ -local char empty_gz[] = { - 0x1f, 0x8b, /* magic gzip id */ - 8, /* compression method is deflate */ - 4, /* there is an extra field */ - 0, 0, 0, 0, /* no modification time provided */ - 0, 0xff, /* no extra flags, no OS */ - 20, 0, 'a', 'p', 16, 0, /* extra field with "ap" subfield */ - 32, 0, 0, 0, 0, 0, 0, 0, /* offset of uncompressed data */ - 32, 0, 0, 0, 0, 0, 0, 0, /* offset of last block */ - 1, 0, 0, 0xff, 0xff, /* empty stored block (last) */ - 0, 0, 0, 0, /* crc */ - 0, 0, 0, 0 /* uncompressed length */ -}; - -/* initialize a log object with locking */ -void *gzlog_open(char *path) -{ - unsigned xlen; - unsigned char temp[20]; - unsigned sub_len; - int good; - gz_log *log; - - /* allocate log structure */ - log = malloc(sizeof(gz_log)); - if (log == NULL) - return NULL; - log->id = GZLOGID; - - /* open file, creating it if necessary, and locking it */ - log->fd = open(path, O_RDWR | O_CREAT, 0600); - if (log->fd < 0) { - free(log); - return NULL; - } - if (lock(log->fd)) { - close(log->fd); - free(log); - return NULL; - } - - /* if file is empty, write new gzip stream */ - if (lseek(log->fd, 0, SEEK_END) == 0) { - if (write(log->fd, empty_gz, sizeof(empty_gz)) != sizeof(empty_gz)) { - log_clean(log); - return NULL; - } - } - - /* check gzip header */ - (void)lseek(log->fd, 0, SEEK_SET); - if (read(log->fd, temp, 12) != 12 || temp[0] != 0x1f || - temp[1] != 0x8b || temp[2] != 8 || (temp[3] & 4) == 0) { - log_clean(log); - return NULL; - } - - /* process extra field to find "ap" sub-field */ - xlen = temp[10] + (temp[11] << 8); - good = 0; - while (xlen) { - if (xlen < 4 || read(log->fd, temp, 4) != 4) - break; - sub_len = temp[2]; - sub_len += temp[3] << 8; - xlen -= 4; - if (memcmp(temp, "ap", 2) == 0 && sub_len == 16) { - good = 1; - break; - } - if (xlen < sub_len) - break; - (void)lseek(log->fd, sub_len, SEEK_CUR); - xlen -= sub_len; - } - if (!good) { - log_clean(log); - return NULL; - } - - /* read in "ap" sub-field */ - log->extra = lseek(log->fd, 0, SEEK_CUR); - if (read(log->fd, temp, 16) != 16) { - log_clean(log); - return NULL; - } - log->mark_off = make_off(temp); - log->last_off = make_off(temp + 8); - - /* get crc, length of gzip file */ - (void)lseek(log->fd, log->last_off, SEEK_SET); - if (read(log->fd, temp, 13) != 13 || - memcmp(temp, "\001\000\000\377\377", 5) != 0) { - log_clean(log); - return NULL; - } - log->crc = make_ulg(temp + 5); - log->len = make_ulg(temp + 9); - - /* set up to write over empty last block */ - (void)lseek(log->fd, log->last_off + 5, SEEK_SET); - log->stored = 0; - return (void *)log; -} - -/* maximum amount to put in a stored block before starting a new one */ -#define MAX_BLOCK 16384 - -/* write a block to a log object */ -int gzlog_write(void *obj, char *data, size_t len) -{ - size_t some; - unsigned char temp[5]; - gz_log *log; - - /* check object */ - log = (gz_log *)obj; - if (log == NULL || log->id != GZLOGID) - return 1; - - /* write stored blocks until all of the input is written */ - do { - some = MAX_BLOCK - log->stored; - if (some > len) - some = len; - if (write(log->fd, data, some) != some) - return 1; - log->crc = crc32(log->crc, data, some); - log->len += some; - len -= some; - data += some; - log->stored += some; - - /* if the stored block is full, end it and start another */ - if (log->stored == MAX_BLOCK) { - (void)lseek(log->fd, log->last_off, SEEK_SET); - temp[0] = 0; - dice_ulg(log->stored + ((unsigned long)(~log->stored) << 16), - temp + 1); - if (write(log->fd, temp, 5) != 5) - return 1; - log->last_off = lseek(log->fd, log->stored, SEEK_CUR); - (void)lseek(log->fd, 5, SEEK_CUR); - log->stored = 0; - } - } while (len); - return 0; -} - -/* recompress the remaining stored deflate data in place */ -local int recomp(gz_log *log) -{ - z_stream strm; - size_t len, max; - unsigned char *in; - unsigned char *out; - unsigned char temp[16]; - - /* allocate space and read it all in (it's around 1 MB) */ - len = log->last_off - log->mark_off; - max = len + (len >> 12) + (len >> 14) + 11; - out = malloc(max); - if (out == NULL) - return 1; - in = malloc(len); - if (in == NULL) { - free(out); - return 1; - } - (void)lseek(log->fd, log->mark_off, SEEK_SET); - if (read(log->fd, in, len) != len) { - free(in); - free(out); - return 1; - } - - /* recompress in memory, decoding stored data as we go */ - /* note: this assumes that unsigned is four bytes or more */ - /* consider not making that assumption */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - if (deflateInit2(&strm, Z_BEST_COMPRESSION, Z_DEFLATED, -15, 8, - Z_DEFAULT_STRATEGY) != Z_OK) { - free(in); - free(out); - return 1; - } - strm.next_in = in; - strm.avail_out = max; - strm.next_out = out; - while (len >= 5) { - if (strm.next_in[0] != 0) - break; - strm.avail_in = strm.next_in[1] + (strm.next_in[2] << 8); - strm.next_in += 5; - len -= 5; - if (strm.avail_in != 0) { - if (len < strm.avail_in) - break; - len -= strm.avail_in; - (void)deflate(&strm, Z_NO_FLUSH); - if (strm.avail_in != 0 || strm.avail_out == 0) - break; - } - } - (void)deflate(&strm, Z_SYNC_FLUSH); - (void)deflateEnd(&strm); - free(in); - if (len != 0 || strm.avail_out == 0) { - free(out); - return 1; - } - - /* overwrite stored data with compressed data */ - (void)lseek(log->fd, log->mark_off, SEEK_SET); - len = max - strm.avail_out; - if (write(log->fd, out, len) != len) { - free(out); - return 1; - } - free(out); - - /* write last empty block, crc, and length */ - log->mark_off = log->last_off = lseek(log->fd, 0, SEEK_CUR); - temp[0] = 1; - dice_ulg(0xffffL << 16, temp + 1); - dice_ulg(log->crc, temp + 5); - dice_ulg(log->len, temp + 9); - if (write(log->fd, temp, 13) != 13) - return 1; - - /* truncate file to discard remaining stored data and old trailer */ - ftruncate(log->fd, lseek(log->fd, 0, SEEK_CUR)); - - /* update extra field to point to new last empty block */ - (void)lseek(log->fd, log->extra, SEEK_SET); - dice_off(log->mark_off, temp); - dice_off(log->last_off, temp + 8); - if (write(log->fd, temp, 16) != 16) - return 1; - return 0; -} - -/* maximum accumulation of stored blocks before compressing */ -#define MAX_STORED 1048576 - -/* close log object */ -int gzlog_close(void *obj) -{ - unsigned char temp[8]; - gz_log *log; - - /* check object */ - log = (gz_log *)obj; - if (log == NULL || log->id != GZLOGID) - return 1; - - /* go to start of most recent block being written */ - (void)lseek(log->fd, log->last_off, SEEK_SET); - - /* if some stuff was put there, update block */ - if (log->stored) { - temp[0] = 0; - dice_ulg(log->stored + ((unsigned long)(~log->stored) << 16), - temp + 1); - if (write(log->fd, temp, 5) != 5) - return 1; - log->last_off = lseek(log->fd, log->stored, SEEK_CUR); - } - - /* write last block (empty) */ - if (write(log->fd, "\001\000\000\377\377", 5) != 5) - return 1; - - /* write updated crc and uncompressed length */ - dice_ulg(log->crc, temp); - dice_ulg(log->len, temp + 4); - if (write(log->fd, temp, 8) != 8) - return 1; - - /* put offset of that last block in gzip extra block */ - (void)lseek(log->fd, log->extra + 8, SEEK_SET); - dice_off(log->last_off, temp); - if (write(log->fd, temp, 8) != 8) - return 1; - - /* if more than 1 MB stored, then time to compress it */ - if (log->last_off - log->mark_off > MAX_STORED) { - if (recomp(log)) - return 1; - } - - /* unlock and close file */ - log_clean(log); - return 0; -} |