Add snapshot compression support into d8.

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 1d798b14bfa3ef3e059f117c1f44b916fdc821df..f4c7846f5273e6dc5106e047febf4814ad6693ae 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -26,8 +26,11 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
-#include <stdlib.h>
+#ifdef COMPRESS_STARTUP_DATA_BZ2
+#include <bzlib.h>
+#endif
 #include <errno.h>
+#include <stdlib.h>
 
 #include "v8.h"
 
@@ -483,7 +486,44 @@ void Shell::AddHistogramSample(void* histogram, int sample) {
 }
 
 
+#ifdef COMPRESS_STARTUP_DATA_BZ2
+class BZip2Decompressor : public v8::StartupDataDecompressor {
+ public:
+  virtual ~BZip2Decompressor() { }
+
+ protected:
+  virtual int DecompressData(char* raw_data,
+                             int* raw_data_size,
+                             const char* compressed_data,
+                             int compressed_data_size) {
+    ASSERT_EQ(v8::StartupData::kBZip2,
+              v8::V8::GetCompressedStartupDataAlgorithm());
+    unsigned int decompressed_size = *raw_data_size;
+    int result =
+        BZ2_bzBuffToBuffDecompress(raw_data,
+                                   &decompressed_size,
+                                   const_cast<char*>(compressed_data),
+                                   compressed_data_size,
+                                   0, 1);
+    if (result == BZ_OK) {
+      *raw_data_size = decompressed_size;
+    }
+    return result;
+  }
+};
+#endif
+
+
 void Shell::Initialize() {
+#ifdef COMPRESS_STARTUP_DATA_BZ2
+  BZip2Decompressor startup_data_decompressor;
+  int bz2_result = startup_data_decompressor.Decompress();
+  if (bz2_result != BZ_OK) {
+    fprintf(stderr, "bzip error code: %d\n", bz2_result);
+    exit(1);
+  }
+#endif
+
   Shell::counter_map_ = new CounterMap();
   // Set up counters
   if (i::StrLength(i::FLAG_map_counters) != 0)