14312d833e
There used to be a (very small) chance that
loading prefix from previous segment
would be confused with a real zstd dictionary.
For that to happen, the prefix needs to start
with the same value as dictionary magic.
That's 1 chance in 4 billions if all values have equal probability.
But in fact, since some values are more common (0x00000000 for example)
others are less common, and dictionary magic was selected to be one of them,
so probabilities are likely even lower.
Anyway, this risk is no down to zero
by adding a new CCtx parameter : ZSTD_p_forceRawDict
Current parameter policy : the parameter "stick" to its CCtx,
so any dictionary loading after ZSTD_p_forceRawDict is set
will be loaded in "raw" ("content only") mode,
even if CCtx is re-used multiple times with multiple different dictionary.
It's up to the user to reset this value differently if it needs so.
|
||
|---|---|---|
| .. | ||
| common | ||
| compress | ||
| decompress | ||
| deprecated | ||
| dictBuilder | ||
| dll | ||
| legacy | ||
| .gitignore | ||
| BUCK | ||
| libzstd.pc.in | ||
| Makefile | ||
| README.md | ||
| zstd.h | ||
Zstandard library files
The lib directory contains several directories. Depending on target use case, it's enough to include only files from relevant directories.
API
Zstandard's stable API is exposed within zstd.h,
at the root of lib directory.
Advanced API
Some additional API may be useful if you're looking into advanced features :
- common/error_public.h : transforms
size_tfunction results into anenum, for precise error handling. - ZSTD_STATIC_LINKING_ONLY : if you define this macro before including
zstd.h, it will give access to advanced and experimental API. These APIs shall never be used with dynamic library ! They are not "stable", their definition may change in the future. Only static linking is allowed.
Modular build
Directory common/ is required in all circumstances.
You can select to support compression only, by just adding files from the compress/ directory,
In a similar way, you can build a decompressor-only library with the decompress/ directory.
Other optional functionalities provided are :
-
dictBuilder/: source files to create dictionaries. The API can be consulted indictBuilder/zdict.h. This module also depends oncommon/andcompress/. -
legacy/: source code to decompress previous versions of zstd, starting fromv0.1. This module also depends oncommon/anddecompress/. Library compilation must include directiveZSTD_LEGACY_SUPPORT = 1. The main API can be consulted inlegacy/zstd_legacy.h. Advanced API from each version can be found in their relevant header file. For example, advanced API for versionv0.4is inlegacy/zstd_v04.h.
Using MinGW+MSYS to create DLL
DLL can be created using MinGW+MSYS with the make libzstd command.
This command creates dll\libzstd.dll and the import library dll\libzstd.lib.
The import library is only required with Visual C++.
The header file zstd.h and the dynamic library dll\libzstd.dll are required to
compile a project using gcc/MinGW.
The dynamic library has to be added to linking options.
It means that if a project that uses ZSTD consists of a single test-dll.c
file it should be linked with dll\libzstd.dll. For example:
gcc $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\libzstd.dll
The compiled executable will require ZSTD DLL which is available at dll\libzstd.dll.
Obsolete streaming API
Streaming is now provided within zstd.h.
Older streaming API is still available within deprecated/zbuff.h.
It will be removed in a future version.
Consider migrating code towards newer streaming API in zstd.h.
Miscellaneous
The other files are not source code. There are :
- LICENSE : contains the BSD license text
- Makefile : script to compile or install zstd library (static and dynamic)
- libzstd.pc.in : for pkg-config (
make install) - README.md : this file