zlib: inflate returns 错误 avail_out?
zlib: inflate returns wrong avail_out?
我想使用 inflate() 来解压缩压缩的缓冲区并将结果写入文件。
因此我使用了this example的代码。我还使用示例代码放气我的缓冲区,这没有问题。但是当我膨胀我的数据时,输出大小似乎是错误的。我的文件输出具有适当膨胀的代码,但末尾填充有“0xCC”,直到写入 CHUNK 字节 (16kB)。输入缓冲区的大小 < CHUNK。文件流设置为O_BINARY。内循环是 运行 两次,一次是 strm.avail_out == 0,然后是 strm.avail_out == CHUNK。这意味着写入了 CHUNK 字节,尽管输出的大小更小。
#define CHUNK 16384
byte chunkBuf[CHUNK];
int inf(byte *src, size_t srcsize, FILE *dest)
{
int ret;
unsigned have;
unsigned char in[CHUNK];
unsigned long srcpos = 0;
z_stream strm;
/* allocate inflate state */
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = 0;
strm.next_in = Z_NULL;
ret = inflateInit(&strm);
if (ret != Z_OK) {
printf("ERR: inf: %i\n",ret);
return ret;
}
/* decompress until deflate stream ends or end of file */
do {
if (srcsize - srcpos > CHUNK) {
memcpy(in,src+srcpos,CHUNK);
strm.avail_in = CHUNK;
srcpos += CHUNK;
} else if (srcsize - srcpos > 0) {
memcpy(in,src+srcpos,srcsize - srcpos);
strm.avail_in = srcsize - srcpos;
srcpos = srcsize;
} else {
break;
}
strm.next_in = in;
/* run inflate() on input until output buffer not full */
do {
strm.avail_out = CHUNK;
strm.next_out = chunkBuf;
ret = inflate(&strm, Z_NO_FLUSH);
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
switch (ret) {
case Z_NEED_DICT:
ret = Z_DATA_ERROR; /* and fall through */
case Z_DATA_ERROR:
case Z_MEM_ERROR:
(void)inflateEnd(&strm);
return ret;
}
have = CHUNK - strm.avail_out;
if (fwrite(chunkBuf, 1, have, dest) != have || ferror(dest)) {
(void)inflateEnd(&strm);
return Z_ERRNO;
}
} while (strm.avail_out == 0);
/* done when inflate() says it's done */
} while (ret != Z_STREAM_END);
/* clean up and return */
(void)inflateEnd(&strm);
return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}
您可能给出了错误的长度来压缩数据后的垃圾。
我想使用 inflate() 来解压缩压缩的缓冲区并将结果写入文件。 因此我使用了this example的代码。我还使用示例代码放气我的缓冲区,这没有问题。但是当我膨胀我的数据时,输出大小似乎是错误的。我的文件输出具有适当膨胀的代码,但末尾填充有“0xCC”,直到写入 CHUNK 字节 (16kB)。输入缓冲区的大小 < CHUNK。文件流设置为O_BINARY。内循环是 运行 两次,一次是 strm.avail_out == 0,然后是 strm.avail_out == CHUNK。这意味着写入了 CHUNK 字节,尽管输出的大小更小。
#define CHUNK 16384
byte chunkBuf[CHUNK];
int inf(byte *src, size_t srcsize, FILE *dest)
{
int ret;
unsigned have;
unsigned char in[CHUNK];
unsigned long srcpos = 0;
z_stream strm;
/* allocate inflate state */
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = 0;
strm.next_in = Z_NULL;
ret = inflateInit(&strm);
if (ret != Z_OK) {
printf("ERR: inf: %i\n",ret);
return ret;
}
/* decompress until deflate stream ends or end of file */
do {
if (srcsize - srcpos > CHUNK) {
memcpy(in,src+srcpos,CHUNK);
strm.avail_in = CHUNK;
srcpos += CHUNK;
} else if (srcsize - srcpos > 0) {
memcpy(in,src+srcpos,srcsize - srcpos);
strm.avail_in = srcsize - srcpos;
srcpos = srcsize;
} else {
break;
}
strm.next_in = in;
/* run inflate() on input until output buffer not full */
do {
strm.avail_out = CHUNK;
strm.next_out = chunkBuf;
ret = inflate(&strm, Z_NO_FLUSH);
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
switch (ret) {
case Z_NEED_DICT:
ret = Z_DATA_ERROR; /* and fall through */
case Z_DATA_ERROR:
case Z_MEM_ERROR:
(void)inflateEnd(&strm);
return ret;
}
have = CHUNK - strm.avail_out;
if (fwrite(chunkBuf, 1, have, dest) != have || ferror(dest)) {
(void)inflateEnd(&strm);
return Z_ERRNO;
}
} while (strm.avail_out == 0);
/* done when inflate() says it's done */
} while (ret != Z_STREAM_END);
/* clean up and return */
(void)inflateEnd(&strm);
return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}
您可能给出了错误的长度来压缩数据后的垃圾。