decompress()

Decompress header cache data. More...

Collaboration diagram for decompress():

Functions
static void *	compr_lz4_decompress (ComprHandle *handle, const char *cbuf, size_t clen)
	Decompress header cache data - Implements ComprOps::decompress() -.
static void *	compr_zlib_decompress (ComprHandle *handle, const char *cbuf, size_t clen)
	Decompress header cache data - Implements ComprOps::decompress() -.
static void *	compr_zstd_decompress (ComprHandle *handle, const char *cbuf, size_t clen)
	Decompress header cache data - Implements ComprOps::decompress() -.

Detailed Description

Decompress header cache data.

Parameters

[in]	handle	Compression handle
[in]	cbuf	Data to be decompressed
[in]	clen	Length of the compressed input data

Return values

ptr	Success, pointer to decompressed data
NULL	Otherwise

Note

This function returns a pointer to data, which will be freed by the close() function.

Function Documentation

compr_lz4_decompress()

static void * compr_lz4_decompress ( ComprHandle * handle, const char * cbuf, size_t clen )

static

Decompress header cache data - Implements ComprOps::decompress() -.

Definition at line 138 of file lz4.c.

{
  if (!handle)
    return NULL;
 
  // Decloak an opaque pointer
  struct Lz4ComprData *cdata = handle;
 
  /* first 4 bytes store the size */
  const unsigned char *cs = (const unsigned char *) cbuf;
  if (clen < 4)
    return NULL;
  if ((clen - 4) > INT_MAX)
    return NULL;
  size_t ulen = cs[0] + (cs[1] << 8) + (cs[2] << 16) + ((size_t) cs[3] << 24);
  if (ulen > INT_MAX)
    return NULL; // LCOV_EXCL_LINE
  if (ulen == 0)
    return (void *) cbuf;
 
  mutt_mem_realloc(&cdata->buf, ulen);
  void *ubuf = cdata->buf;
  const char *data = cbuf;
  int rc = LZ4_decompress_safe(data + 4, ubuf, clen - 4, ulen);
  if (rc < 0)
    return NULL;
 
  return ubuf;
}

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compr_zlib_decompress()

static void * compr_zlib_decompress ( ComprHandle * handle, const char * cbuf, size_t clen )

static

Decompress header cache data - Implements ComprOps::decompress() -.

Definition at line 136 of file zlib.c.

{
  if (!handle)
    return NULL;
 
  // Decloak an opaque pointer
  struct ZlibComprData *cdata = handle;
 
  /* first 4 bytes store the size */
  const unsigned char *cs = (const unsigned char *) cbuf;
  if (clen < 4)
    return NULL;
  uLong ulen = cs[0] + (cs[1] << 8) + (cs[2] << 16) + ((uLong) cs[3] << 24);
  if (ulen == 0)
    return NULL;
 
  mutt_mem_realloc(&cdata->buf, ulen);
  Bytef *ubuf = cdata->buf;
  cs = (const unsigned char *) cbuf;
  int rc = uncompress(ubuf, &ulen, cs + 4, clen - 4);
  if (rc != Z_OK)
    return NULL;
 
  return ubuf;
}

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compr_zstd_decompress()

static void * compr_zstd_decompress ( ComprHandle * handle, const char * cbuf, size_t clen )

static

Decompress header cache data - Implements ComprOps::decompress() -.

Definition at line 139 of file zstd.c.

{
  if (!handle)
    return NULL;
 
  // Decloak an opaque pointer
  struct ZstdComprData *cdata = handle;
 
  unsigned long long len = ZSTD_getFrameContentSize(cbuf, clen);
  if (len == ZSTD_CONTENTSIZE_UNKNOWN)
    return NULL; // LCOV_EXCL_LINE
  else if (len == ZSTD_CONTENTSIZE_ERROR)
    return NULL;
  else if (len == 0)
    return NULL; // LCOV_EXCL_LINE
  mutt_mem_realloc(&cdata->buf, len);
 
  size_t rc = ZSTD_decompressDCtx(cdata->dctx, cdata->buf, len, cbuf, clen);
  if (ZSTD_isError(rc))
    return NULL; // LCOV_EXCL_LINE
 
  return cdata->buf;
}

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