Bug 888658 - Add LZ4 compression to mfbt. r=jwalden,vlad

mfbt/Compression.cpp

@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Compression.h"
+#include "mozilla/CheckedInt.h"
+using namespace mozilla::Compression;
+
+namespace {
+
+#include "lz4.c"
+
+}/* anonymous namespace */
+
+/* Our wrappers */
+
+size_t
+LZ4::compress(const char* source, size_t inputSize, char* dest)
+{
+    CheckedInt<int> inputSizeChecked = inputSize;
+    MOZ_ASSERT(inputSizeChecked.isValid());
+    return LZ4_compress(source, dest, inputSizeChecked.value());
+}
+
+size_t
+LZ4::compressLimitedOutput(const char* source, size_t inputSize, char* dest, size_t maxOutputSize)
+{
+    CheckedInt<int> inputSizeChecked = inputSize;
+    MOZ_ASSERT(inputSizeChecked.isValid());
+    CheckedInt<int> maxOutputSizeChecked = maxOutputSize;
+    MOZ_ASSERT(maxOutputSizeChecked.isValid());
+    return LZ4_compress_limitedOutput(source, dest, inputSizeChecked.value(),
+                                      maxOutputSizeChecked.value());
+}
+
+bool
+LZ4::decompress(const char* source, char* dest, size_t outputSize)
+{
+    CheckedInt<int> outputSizeChecked = outputSize;
+    MOZ_ASSERT(outputSizeChecked.isValid());
+    int ret = LZ4_decompress_fast(source, dest, outputSizeChecked.value());
+    return ret >= 0;
+}
+
+bool
+LZ4::decompress(const char* source, size_t inputSize, char* dest, size_t maxOutputSize,
+                size_t *outputSize)
+{
+    CheckedInt<int> maxOutputSizeChecked = maxOutputSize;
+    MOZ_ASSERT(maxOutputSizeChecked.isValid());
+    CheckedInt<int> inputSizeChecked = inputSize;
+    MOZ_ASSERT(inputSizeChecked.isValid());
+
+    int ret = LZ4_decompress_safe(source, dest, inputSizeChecked.value(),
+                                  maxOutputSizeChecked.value());
+    if (ret >= 0) {
+        *outputSize = ret;
+        return true;
+    } else {
+        *outputSize = 0;
+        return false;
+    }
+}
+