pub const ZSTD_CONTENTSIZE_UNKNOWN: i32 = -1;Expand description
ZSTD_getFrameContentSize() : requires v1.3.0+
src should point to the start of a ZSTD encoded frame.
srcSize must be at least as large as the frame header.
hint : any size >= ZSTD_frameHeaderSize_max is large enough.
@return : - decompressed size of src frame content, if known
- ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
- ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
note 1 : a 0 return value means the frame is valid but “empty”.
When invoking this method on a skippable frame, it will return 0.
note 2 : decompressed size is an optional field, it may not be present (typically in streaming mode).
When return==ZSTD_CONTENTSIZE_UNKNOWN, data to decompress could be any size.
In which case, it’s necessary to use streaming mode to decompress data.
Optionally, application can rely on some implicit limit,
as ZSTD_decompress() only needs an upper bound of decompressed size.
(For example, data could be necessarily cut into blocks <= 16 KB).
note 3 : decompressed size is always present when compression is completed using single-pass functions,
such as ZSTD_compress(), ZSTD_compressCCtx() ZSTD_compress_usingDict() or ZSTD_compress_usingCDict().
note 4 : decompressed size can be very large (64-bits value),
potentially larger than what local system can handle as a single memory segment.
In which case, it’s necessary to use streaming mode to decompress data.
note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
Always ensure return value fits within application’s authorized limits.
Each application can set its own limits.
note 6 : This function replaces ZSTD_getDecompressedSize()