Compress Observatory assets

runtime/bin/main.cc

 // Copyright (c) 2012, 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 <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_tools_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/directory.h"
 #include "bin/embedded_dart_io.h"
 #include "bin/eventhandler.h"
 #include "bin/extensions.h"
 #include "bin/file.h"
 #include "bin/isolate_data.h"
 #include "bin/log.h"
 #include "bin/platform.h"
 #include "bin/process.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
 #include "bin/vmservice_impl.h"
 #include "platform/globals.h"
 #include "platform/hashmap.h"
 #include "platform/text_buffer.h"
+#include "zlib/zlib.h"
 
 namespace dart {
 namespace bin {
 
 // vm_isolate_snapshot_buffer points to a snapshot for the vm isolate if we
 // link in a snapshot otherwise it is initialized to NULL.
 extern const uint8_t* vm_isolate_snapshot_buffer;
 
 // isolate_snapshot_buffer points to a snapshot for an isolate if we link in a
 // snapshot otherwise it is initialized to NULL.
@@ skipping 1236 matching lines @@
 
   // No restart.
   return false;
 }
 
 #undef CHECK_RESULT
 
 extern unsigned int observatory_assets_archive_len;
 extern const uint8_t* observatory_assets_archive;
 
-Dart_Handle GetVMServiceAssetsArchiveCallback() {
-  return DartUtils::MakeUint8Array(
-      observatory_assets_archive,
-      observatory_assets_archive_len);
+
+// |input| is assumed to be a gzipped stream.
+// This function allocates the output buffer in the C heap and the caller
+// is responsible for freeing it.
+void Decompress(const uint8_t* input, unsigned int input_len,
+                uint8_t** output, unsigned int* output_length) {
+  ASSERT(input != NULL);
+  ASSERT(input_len > 0);
+  ASSERT(output != NULL);
+  ASSERT(output_length != NULL);
+
+  // Initialize output.
+  *output = NULL;
+  *output_length = 0;
+
+  const intptr_t kChunkSize = 256 * 1024;
+  uint8_t chunk_out[kChunkSize];
+  z_stream strm;
+  strm.zalloc = Z_NULL;
+  strm.zfree = Z_NULL;
+  strm.opaque = Z_NULL;
+  strm.avail_in = 0;
+  strm.next_in = 0;
+  int ret = inflateInit2(&strm, 32 + MAX_WBITS);
+  ASSERT(ret == Z_OK);
+
+  unsigned int input_cursor = 0;
+  unsigned int output_cursor = 0;
+  do {
+    // Setup input.
+    unsigned int size_in = input_len - input_cursor;
+    if (size_in > kChunkSize) {
+      size_in = kChunkSize;
+    }
+    strm.avail_in = size_in;
+    strm.next_in = const_cast<uint8_t*>(&input[input_cursor]);
+
+    // Inflate until we've exhausted the current input chunk.
+    do {
+      // Setup output.
+      strm.avail_out = kChunkSize;
+      strm.next_out = &chunk_out[0];
+      // Inflate.
+      ret = inflate(&strm, Z_SYNC_FLUSH);
+      // We either hit the end of the stream or made forward progress.
+      ASSERT((ret == Z_STREAM_END) || (ret == Z_OK));
+      // Grow output buffer size.
+      unsigned int size_out = kChunkSize - strm.avail_out;
+      *output_length += size_out;
+      *output = reinterpret_cast<uint8_t*>(realloc(*output, *output_length));
+      // Copy output.
+      memmove(&((*output)[output_cursor]), &chunk_out[0], size_out);
+      output_cursor += size_out;
+    } while (strm.avail_out == 0);
+
+    // We've processed size_in bytes.
+    input_cursor += size_in;
+
+    // We're finished decompressing when zlib tells us.
+  } while (ret != Z_STREAM_END);
+
+  inflateEnd(&strm);
 }
 
 
+Dart_Handle GetVMServiceAssetsArchiveCallback() {
+  uint8_t* decompressed = NULL;
+  unsigned int decompressed_len = 0;
+  Decompress(observatory_assets_archive,
+             observatory_assets_archive_len,
+             &decompressed,
+             &decompressed_len);
+  Dart_Handle tar_file = DartUtils::MakeUint8Array(decompressed,
+                                                   decompressed_len);
+  // Free decompressed memory as it has been copied into a Dart array.
+  free(decompressed);
+  return tar_file;
+}
+
+
 void main(int argc, char** argv) {
   char* script_name;
   const int EXTRA_VM_ARGUMENTS = 2;
   CommandLineOptions vm_options(argc + EXTRA_VM_ARGUMENTS);
   CommandLineOptions dart_options(argc);
   bool print_flags_seen = false;
   bool verbose_debug_seen = false;
 
   vm_options.AddArgument("--no_write_protect_code");
   // Perform platform specific initialization.
@@ skipping 117 matching lines @@
   Platform::Exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }