util: create some standalone compression helpers

This will be used by the following patch. It allows us to detangle
compression from the disk cache code, and abstract the underlying
compression libraries we use.

Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9593>

src/util/compress.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright © 2021 Valve Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <assert.h>
+
+#include "zlib.h"
+
+#ifdef HAVE_ZSTD
+#include "zstd.h"
+#endif
+
+#include "util/compress.h"
+
+/* 3 is the recomended level, with 22 as the absolute maximum */
+#define ZSTD_COMPRESSION_LEVEL 3
+
+size_t
+util_compress_max_compressed_len(size_t in_data_size)
+{
+#ifdef HAVE_ZSTD
+   /* from the zstd docs (https://facebook.github.io/zstd/zstd_manual.html):
+    * compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
+    */
+   return ZSTD_compressBound(in_data_size);
+#else
+   /* From https://zlib.net/zlib_tech.html:
+    *
+    *    "In the worst possible case, where the other block types would expand
+    *    the data, deflation falls back to stored (uncompressed) blocks. Thus
+    *    for the default settings used by deflateInit(), compress(), and
+    *    compress2(), the only expansion is an overhead of five bytes per 16 KB
+    *    block (about 0.03%), plus a one-time overhead of six bytes for the
+    *    entire stream."
+    */
+   size_t num_blocks = (in_data_size + 16383) / 16384; /* round up blocks */
+   return in_data_size + 6 + (num_blocks * 5);        
+#endif
+}
+
+/* Compress data and return the size of the compressed data */
+size_t
+util_compress_deflate(uint8_t *in_data, size_t in_data_size,
+                      uint8_t *out_data, size_t out_buff_size)
+{
+#ifdef HAVE_ZSTD
+   size_t ret = ZSTD_compress(out_data, out_buff_size, in_data, in_data_size,
+                              ZSTD_COMPRESSION_LEVEL);
+   if (ZSTD_isError(ret))
+      return 0;
+
+   return ret;
+#else
+   size_t compressed_size = 0;
+
+   /* allocate deflate state */
+   z_stream strm;
+   strm.zalloc = Z_NULL;
+   strm.zfree = Z_NULL;
+   strm.opaque = Z_NULL;
+   strm.next_in = in_data;
+   strm.next_out = out_data;
+   strm.avail_in = in_data_size;
+   strm.avail_out = out_buff_size;
+
+   int ret = deflateInit(&strm, Z_BEST_COMPRESSION);
+   if (ret != Z_OK) {
+       (void) deflateEnd(&strm);
+       return 0;
+   }
+
+   /* compress until end of in_data */
+   ret = deflate(&strm, Z_FINISH);
+
+   /* stream should be complete */
+   assert(ret == Z_STREAM_END);
+   if (ret == Z_STREAM_END) {
+       compressed_size = strm.total_out;
+   }
+
+   /* clean up and return */
+   (void) deflateEnd(&strm);
+   return compressed_size;
+# endif
+}
+
+/**
+ * Decompresses data, returns true if successful.
+ */
+bool
+util_compress_inflate(uint8_t *in_data, size_t in_data_size,
+                      uint8_t *out_data, size_t out_data_size)
+{
+#ifdef HAVE_ZSTD
+   size_t ret = ZSTD_decompress(out_data, out_data_size, in_data, in_data_size);
+   return !ZSTD_isError(ret);
+#else
+   z_stream strm;
+
+   /* allocate inflate state */
+   strm.zalloc = Z_NULL;
+   strm.zfree = Z_NULL;
+   strm.opaque = Z_NULL;
+   strm.next_in = in_data;
+   strm.avail_in = in_data_size;
+   strm.next_out = out_data;
+   strm.avail_out = out_data_size;
+
+   int ret = inflateInit(&strm);
+   if (ret != Z_OK)
+      return false;
+
+   ret = inflate(&strm, Z_NO_FLUSH);
+   assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
+
+   /* Unless there was an error we should have decompressed everything in one
+    * go as we know the uncompressed file size.
+    */
+   if (ret != Z_STREAM_END) {
+      (void)inflateEnd(&strm);
+      return false;
+   }
+   assert(strm.avail_out == 0);
+
+   /* clean up and return */
+   (void)inflateEnd(&strm);
+   return true;
+#endif
+}

src/util/compress.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright © 2021 Valve Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include <inttypes.h>
+
+size_t
+util_compress_max_compressed_len(size_t in_data_size);
+
+bool
+util_compress_inflate(uint8_t *in_data, size_t in_data_size,
+                      uint8_t *out_data, size_t out_data_size);
+
+size_t
+util_compress_deflate(uint8_t *in_data, size_t in_data_size,
+                      uint8_t *out_data, size_t out_buff_size);

src/util/meson.build

@@ -35,6 +35,8 @@ files_mesa_util = files(
   'build_id.h',
   'cnd_monotonic.h',
   'compiler.h',
+  'compress.c',
+  'compress.h',
   'crc32.c',
   'crc32.h',
   'dag.c',