Move ZstdStreamDecompressor into decompression

Summary:
**Context:** Group Proxygen decompression classes and helpers in `proxygen::decompression`.

**This diff:** Move `ZstdStreamDecompressor` and its associated constants into that namespace and update its live callers across fbsource. Include embedded C++ callers and retain existing include paths.

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landed-with-radar-review

Differential Revision: D126117909

fbshipit-source-id: e77f003a6b475376187462011b43b05900614c7c

proxygen/httpserver/filters/DecompressionFilter.cpp

@@ -17,7 +17,8 @@ void DecompressionFilter::onRequest(std::unique_ptr<HTTPMessage> msg) noexcept {
   auto contentEncoding =
       headers.getSingleOrNullptr(HTTP_HEADER_CONTENT_ENCODING);
   if (contentEncoding && *contentEncoding == "zstd") {
-    decompressor_ = std::make_unique<ZstdStreamDecompressor>();
+    decompressor_ =
+        std::make_unique<proxygen::decompression::ZstdStreamDecompressor>();
     headers.remove(HTTP_HEADER_CONTENT_ENCODING);
     headers.remove(HTTP_HEADER_CONTENT_LENGTH);
   }

proxygen/httpserver/filters/tests/CompressionFilterTest.cpp

@@ -49,7 +49,7 @@ struct ZlibTest {
 
 struct ZstdTest {
   static std::unique_ptr<StreamDecompressor> makeDecompressor() {
-    return std::make_unique<ZstdStreamDecompressor>();
+    return std::make_unique<proxygen::decompression::ZstdStreamDecompressor>();
   }
   static std::string getExpectedEncoding() {
     return "zstd";

proxygen/lib/http/coro/filters/DecompressionFilter.cpp

@@ -103,7 +103,8 @@ void DecompressionIngressFilter::initializeWithHTTPMessage(HTTPMessage& msg) {
       statsCallback_->onDecompressionAlgo(std::string(it->name));
     }
     if (it->type == CompressionType::ZSTD) {
-      decompressor_ = std::make_unique<ZstdStreamDecompressor>();
+      decompressor_ =
+          std::make_unique<proxygen::decompression::ZstdStreamDecompressor>();
     } else {
       decompressor_ =
           std::make_unique<proxygen::decompression::ZlibStreamDecompressor>(

proxygen/lib/http/coro/filters/test/CompressionFilterTests.cpp

@@ -40,7 +40,7 @@ struct ZlibTest {
 
 struct ZstdTest {
   static std::unique_ptr<StreamDecompressor> makeDecompressor() {
-    return std::make_unique<ZstdStreamDecompressor>();
+    return std::make_unique<proxygen::decompression::ZstdStreamDecompressor>();
   }
   static std::string getExpectedEncoding() {
     return "zstd";

proxygen/lib/utils/ZstdStreamDecompressor.cpp

@@ -11,7 +11,7 @@
 #include <folly/io/Cursor.h>
 #include <folly/io/IOBuf.h>
 
-namespace proxygen {
+namespace proxygen::decompression {
 
 void ZstdStreamDecompressor::freeDCtx(ZSTD_DCtx* dctx) {
   ZSTD_freeDCtx(dctx);
@@ -88,4 +88,4 @@ std::unique_ptr<folly::IOBuf> ZstdStreamDecompressor::decompress(
 
   return out;
 }
-} // namespace proxygen
+} // namespace proxygen::decompression

proxygen/lib/utils/ZstdStreamDecompressor.h

@@ -26,7 +26,7 @@
 
 #include <proxygen/lib/utils/StreamDecompressor.h>
 
-namespace proxygen {
+namespace proxygen::decompression {
 
 constexpr uint64_t kDefaultMaxZstdDecompressionRatio = 1000;
 
@@ -72,4 +72,4 @@ class ZstdStreamDecompressor : public StreamDecompressor {
   uint64_t totalInputBytes_{0};
   uint64_t totalOutputBytes_{0};
 };
-} // namespace proxygen
+} // namespace proxygen::decompression

proxygen/lib/utils/test/ZstdTests.cpp

@@ -42,7 +42,8 @@ std::unique_ptr<folly::IOBuf> makeBuf(uint32_t size) {
 void verify(std::unique_ptr<IOBuf> original,
             std::unique_ptr<IOBuf> compressed,
             bool reuseBuf) {
-  auto zd = std::make_unique<ZstdStreamDecompressor>(reuseBuf);
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
+      reuseBuf);
 
   auto decompressed = zd->decompress(compressed.get());
   ASSERT_FALSE(zd->hasError()) << "Decompression error.";
@@ -56,7 +57,8 @@ void verify(std::unique_ptr<IOBuf> original,
 void verifyPieces(std::unique_ptr<IOBuf> original,
                   std::vector<std::unique_ptr<IOBuf>> compressed,
                   bool reuseBuf) {
-  auto zd = std::make_unique<ZstdStreamDecompressor>(reuseBuf);
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
+      reuseBuf);
 
   auto decompressed = folly::IOBuf::create(0);
 
@@ -260,7 +262,7 @@ TEST_F(ZstdTests, MaxDecompressionRatio_FailsWhenRatioTooSmall) {
   auto compressed = compress(original);
   ASSERT_NE(compressed, nullptr);
 
-  auto zd = std::make_unique<ZstdStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
       /*reuseOutBuf=*/false, /*maxDecompressionRatio=*/10);
 
   auto decompressed = zd->decompress(compressed.get());
@@ -275,7 +277,7 @@ TEST_F(ZstdTests, MaxDecompressionRatio_PassesWhenRatioLargeEnough) {
   ASSERT_NE(compressed, nullptr);
 
   // Use a very large ratio so decompression succeeds.
-  auto zd = std::make_unique<ZstdStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
       /*reuseOutBuf=*/false, /*maxDecompressionRatio=*/1000000);
 
   auto decompressed = zd->decompress(compressed.get());
@@ -291,7 +293,7 @@ TEST_F(ZstdTests, MaxDecompressionRatio_PassesWhenExplicitlyUnlimited) {
   ASSERT_NE(compressed, nullptr);
 
   // Explicitly opt out of ratio limit.
-  auto zd = std::make_unique<ZstdStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
       /*reuseOutBuf=*/false, /*maxDecompressionRatio=*/std::nullopt);
 
   auto decompressed = zd->decompress(compressed.get());
@@ -308,7 +310,7 @@ TEST_F(ZstdTests, MaxDecompressionRatio_StreamingChunksFailure) {
   auto compressed = compress(original);
   ASSERT_NE(compressed, nullptr);
 
-  auto zd = std::make_unique<ZstdStreamDecompressor>(
+  auto zd = std::make_unique<proxygen::decompression::ZstdStreamDecompressor>(
       /*reuseOutBuf=*/false, /*maxDecompressionRatio=*/10);
 
   // Split compressed data into small chunks.