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-rw-r--r--cpukit/zlib/examples/gzlog.c413
1 files changed, 0 insertions, 413 deletions
diff --git a/cpukit/zlib/examples/gzlog.c b/cpukit/zlib/examples/gzlog.c
deleted file mode 100644
index f71f817c8b..0000000000
--- a/cpukit/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;
-}
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