Compression: Add String Helpers for getUncompressedLength and canUncompress

Summary: As title.

Reviewed By: yfeldblum

Differential Revision: D18351375

fbshipit-source-id: 594270e7b6b7056f7223fa7575ee33fed8f7d266

folly/compression/Compression.cpp

@@ -264,6 +264,13 @@ bool Codec::canUncompress(const IOBuf*, Optional<uint64_t>) const {
   return false;
 }
 
+bool Codec::canUncompress(
+    StringPiece data,
+    Optional<uint64_t> uncompressedLength) const {
+  auto buf = IOBuf::wrapBufferAsValue(data.data(), data.size());
+  return canUncompress(&buf, uncompressedLength);
+}
+
 std::string Codec::doCompressString(const StringPiece data) {
   const IOBuf inputBuffer{IOBuf::WRAP_BUFFER, data};
   auto outputBuffer = doCompress(&inputBuffer);
@@ -305,6 +312,13 @@ Optional<uint64_t> Codec::getUncompressedLength(
   return doGetUncompressedLength(data, uncompressedLength);
 }
 
+Optional<uint64_t> Codec::getUncompressedLength(
+    StringPiece data,
+    Optional<uint64_t> uncompressedLength) const {
+  auto buf = IOBuf::wrapBufferAsValue(data.data(), data.size());
+  return getUncompressedLength(&buf, uncompressedLength);
+}
+
 Optional<uint64_t> Codec::doGetUncompressedLength(
     const folly::IOBuf*,
     Optional<uint64_t> uncompressedLength) const {

folly/compression/Compression.h

@@ -210,6 +210,13 @@ class Codec {
       const folly::IOBuf* data,
       folly::Optional<uint64_t> uncompressedLength = folly::none) const;
 
+  /**
+   * Helper wrapper around getUncompressedLength(IOBuf)
+   */
+  folly::Optional<uint64_t> getUncompressedLength(
+      folly::StringPiece data,
+      folly::Optional<uint64_t> uncompressedLength = folly::none) const;
+
  protected:
   Codec(
       CodecType type,
@@ -236,6 +243,13 @@ class Codec {
       const folly::IOBuf* data,
       folly::Optional<uint64_t> uncompressedLength = folly::none) const;
 
+  /**
+   * Helper wrapper around canUncompress(IOBuf)
+   */
+  bool canUncompress(
+      folly::StringPiece data,
+      folly::Optional<uint64_t> uncompressedLength = folly::none) const;
+
  private:
   // default: no limits (save for special value UNKNOWN_UNCOMPRESSED_LENGTH)
   virtual uint64_t doMaxUncompressedLength() const;

folly/compression/test/CompressionTest.cpp

@@ -534,22 +534,34 @@ TEST_P(StreamingUnitTest, maxCompressedLength) {
 
 TEST_P(StreamingUnitTest, getUncompressedLength) {
   auto const empty = IOBuf::create(0);
+  EXPECT_EQ(uint64_t(0), codec_->getUncompressedLength(""));
   EXPECT_EQ(uint64_t(0), codec_->getUncompressedLength(empty.get()));
+  EXPECT_EQ(uint64_t(0), codec_->getUncompressedLength(""));
   EXPECT_EQ(uint64_t(0), codec_->getUncompressedLength(empty.get(), 0));
   EXPECT_ANY_THROW(codec_->getUncompressedLength(empty.get(), 1));
 
   auto const data = IOBuf::wrapBuffer(randomDataHolder.data(100));
   auto const compressed = codec_->compress(data.get());
+  auto const compressedString =
+      StringPiece(ByteRange(data->data(), data->length()));
 
   if (auto const length = codec_->getUncompressedLength(data.get())) {
     EXPECT_EQ(100, *length);
   }
+  if (auto const length = codec_->getUncompressedLength(compressedString)) {
+    EXPECT_EQ(100, *length);
+  }
   EXPECT_EQ(uint64_t(100), codec_->getUncompressedLength(data.get(), 100));
+  EXPECT_EQ(
+      uint64_t(100), codec_->getUncompressedLength(compressedString, 100));
   // If the uncompressed length is stored in the frame, then make sure it throws
   // when it is given the wrong length.
   if (codec_->getUncompressedLength(data.get()) == uint64_t(100)) {
     EXPECT_ANY_THROW(codec_->getUncompressedLength(data.get(), 200));
   }
+  if (codec_->getUncompressedLength(compressedString) == uint64_t(100)) {
+    EXPECT_ANY_THROW(codec_->getUncompressedLength(compressedString, 200));
+  }
 }
 
 TEST_P(StreamingUnitTest, emptyData) {