xref: /netbsd-src/external/bsd/zstd/dist/build/single_file_libs/README.md (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
1*3117ece4Schristos# Single File Zstandard Libraries
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3*3117ece4SchristosThe script `combine.sh` creates an _amalgamated_ source file that can be used with or without `zstd.h`. This isn't a _header-only_ file but it does offer a similar level of simplicity when integrating into a project.
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5*3117ece4SchristosAll it now takes to support Zstd in your own projects is the addition of a single file, two if using the header, with no configuration or further build steps.
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7*3117ece4SchristosDecompressor
8*3117ece4Schristos------------
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10*3117ece4SchristosThis is the most common use case. The decompression library is small, adding, for example, 26kB to an Emscripten compiled WebAssembly project. Native implementations add a little more, 40-70kB depending on the compiler and platform.
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12*3117ece4SchristosCreate `zstddeclib.c` from the Zstd source using:
13*3117ece4Schristos```
14*3117ece4Schristoscd zstd/build/single_file_libs
15*3117ece4Schristospython3 combine.py -r ../../lib -x legacy/zstd_legacy.h -o zstddeclib.c zstddeclib-in.c
16*3117ece4Schristos```
17*3117ece4SchristosThen add the resulting file to your project (see the [example files](examples)).
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19*3117ece4Schristos`create_single_file_decoder.sh` will run the above script, creating the file `zstddeclib.c` (`build_decoder_test.sh` will also create `zstddeclib.c`, then compile and test the result).
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21*3117ece4SchristosFull Library
22*3117ece4Schristos------------
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24*3117ece4SchristosThe same tool can amalgamate the entire Zstd library for ease of adding both compression and decompression to a project. The [roundtrip example](examples/roundtrip.c) uses the original `zstd.h` with the remaining source files combined into `zstd.c` (currently just over 1.2MB) created from `zstd-in.c`. As with the standalone decoder the most useful compile flags have already been rolled-in and the resulting file can be added to a project as-is.
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26*3117ece4SchristosCreate `zstd.c` from the Zstd source using:
27*3117ece4Schristos```
28*3117ece4Schristoscd zstd/build/single_file_libs
29*3117ece4Schristospython3 combine.py -r ../../lib -x legacy/zstd_legacy.h -k zstd.h -o zstd.c zstd-in.c
30*3117ece4Schristos```
31*3117ece4SchristosIt's possible to create a compressor-only library but since the decompressor is so small in comparison this doesn't bring much of a gain (but for the curious, simply remove the files in the _decompress_ section at the end of `zstd-in.c`).
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33*3117ece4Schristos`create_single_file_library.sh` will run the script to create `zstd.c` (`build_library_test.sh` will also create `zstd.c`, then compile and test the result).
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