[standalone] Automatically decompress gzip'd resources, including sources and script snapshots.

runtime/bin/loader.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/loader.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/dfe.h"
 #include "bin/extensions.h"
 #include "bin/file.h"
+#include "bin/gzip.h"
 #include "bin/lockers.h"
 #include "bin/utils.h"
 #include "include/dart_tools_api.h"
 #include "platform/growable_array.h"
 
 namespace dart {
 namespace bin {
 
 // Development flag.
 static bool trace_loader = false;
@@ skipping 289 matching lines @@
       return;
     }
 
     (*dependencies)[i] =
         StringUtils::StrNDup(reinterpret_cast<const char*>(scoped_file_path),
                              scoped_file_path_length);
     free(resolved_uri);
   }
 }
 
+class ScopedDecompress : public ValueObject {
+ public:
+  ScopedDecompress(const uint8_t** payload, intptr_t* payload_length)
+      : payload_(payload),
+        payload_length_(payload_length),
+        decompressed_(NULL) {
+    DartUtils::MagicNumber payload_type =
+        DartUtils::SniffForMagicNumber(*payload, *payload_length);
+    if (payload_type == DartUtils::kGzipMagicNumber) {
+      int64_t start = Dart_TimelineGetMicros();
+      intptr_t decompressed_length = 0;
+      Decompress(*payload, *payload_length, &decompressed_,
+                 &decompressed_length);
+      int64_t end = Dart_TimelineGetMicros();
+      Dart_TimelineEvent("Decompress", start, end, Dart_Timeline_Event_Duration,
+                         0, NULL, NULL);
+      *payload_ = decompressed_;
+      *payload_length_ = decompressed_length;
+    }
+  }
+
+  ~ScopedDecompress() {
+    if (decompressed_ != NULL) {
+      free(decompressed_);
+    }
+  }
+
+ private:
+  const uint8_t** payload_;
+  intptr_t* payload_length_;
+  uint8_t* decompressed_;
+};
+
 bool Loader::ProcessResultLocked(Loader* loader, Loader::IOResult* result) {
   // We have to copy everything we care about out of |result| because after
   // dropping the lock below |result| may no longer valid.
   Dart_Handle uri =
       Dart_NewStringFromCString(reinterpret_cast<char*>(result->uri));
   Dart_Handle resolved_uri =
       Dart_NewStringFromCString(reinterpret_cast<char*>(result->resolved_uri));
   Dart_Handle library_uri = Dart_Null();
   if (result->library_uri != NULL) {
     library_uri =
@@ skipping 50 matching lines @@
     if (Dart_IsError(result)) {
       loader->error_ = result;
       return false;
     }
     return true;
   }
 
   // Check for payload and load accordingly.
   const uint8_t* payload = result->payload;
   intptr_t payload_length = result->payload_length;
+
+  // Decompress if gzip'd.
+  ScopedDecompress decompress(&payload, &payload_length);
+
   const DartUtils::MagicNumber payload_type =
-      DartUtils::SniffForMagicNumber(&payload, &payload_length);
+      DartUtils::SniffForMagicNumber(payload, payload_length);
   Dart_Handle source = Dart_Null();
   if (payload_type == DartUtils::kUnknownMagicNumber) {
-    source = Dart_NewStringFromUTF8(result->payload, result->payload_length);
+    source = Dart_NewStringFromUTF8(payload, payload_length);
     if (Dart_IsError(source)) {
       loader->error_ =
           DartUtils::NewError("%s is not a valid UTF-8 script",
                               reinterpret_cast<char*>(result->uri));
       return false;
     }
   }
   intptr_t tag = result->tag;
 
   // No touching.
@@ skipping 11 matching lines @@
       dart_result = Dart_LoadLibrary(uri, resolved_uri, source, 0, 0);
       break;
     case Dart_kSourceTag: {
       ASSERT(library_uri != Dart_Null());
       Dart_Handle library = Dart_LookupLibrary(library_uri);
       ASSERT(!Dart_IsError(library));
       dart_result = Dart_LoadSource(library, uri, resolved_uri, source, 0, 0);
     } break;
     case Dart_kScriptTag:
       if (payload_type == DartUtils::kSnapshotMagicNumber) {
+        DartUtils::SkipSnapshotMagicNumber(&payload, &payload_length);
         dart_result = Dart_LoadScriptFromSnapshot(payload, payload_length);
         reload_extensions = true;
       } else if (payload_type == DartUtils::kKernelMagicNumber) {
         // TODO(27590): This code path is only hit when trying to spawn
         // isolates. We currently do not have support for neither
         // `Isolate.spawn()` nor `Isolate.spawnUri()` with kernel-based
         // frontend.
         Dart_Handle kernel_binary = reinterpret_cast<Dart_Handle>(
             Dart_ReadKernelBinary(payload, payload_length));
         dart_result = Dart_LoadScript(uri, resolved_uri, kernel_binary, 0, 0);
@@ skipping 458 matching lines @@
   MutexLocker ml(loader_infos_lock_);
   Loader* loader = LoaderForLocked(dest_port_id);
   if (loader == NULL) {
     return;
   }
   loader->QueueMessage(message);
 }
 
 }  // namespace bin
 }  // namespace dart