Add support for the Runtime to consume precompiled snapshot BLOB

Author: atanasovg

src/jni/Constants.cpp

@@ -12,3 +12,4 @@ bool Constants::V8_CACHE_COMPILED_CODE = false;
 bool Constants::V8_HEAP_SNAPSHOT = false;
 std::string Constants::V8_STARTUP_FLAGS = "";
 std::string Constants::V8_HEAP_SNAPSHOT_SCRIPT = "";
+std::string Constants::V8_HEAP_SNAPSHOT_BLOB = "";

src/jni/Constants.h

@@ -13,6 +13,7 @@ class Constants
 	static std::string APP_ROOT_FOLDER_PATH;
 	static std::string V8_STARTUP_FLAGS;
 	static std::string V8_HEAP_SNAPSHOT_SCRIPT;
+	static std::string V8_HEAP_SNAPSHOT_BLOB;
 	static bool V8_CACHE_COMPILED_CODE;
 	static bool V8_HEAP_SNAPSHOT;
 

src/jni/Runtime.cpp

@@ -135,7 +135,9 @@ void Runtime::Init(jstring filesPath, bool verboseLoggingEnabled, jstring packag
 	Constants::V8_HEAP_SNAPSHOT = (bool)snapshot;
 	JniLocalRef snapshotScript(m_env.GetObjectArrayElement(args, 3));
 	Constants::V8_HEAP_SNAPSHOT_SCRIPT = ArgConverter::jstringToString(snapshotScript);
-	JniLocalRef profilerOutputDir(m_env.GetObjectArrayElement(args, 4));
+	JniLocalRef snapshotBlob(m_env.GetObjectArrayElement(args, 4));
+	Constants::V8_HEAP_SNAPSHOT_BLOB = ArgConverter::jstringToString(snapshotBlob);
+	JniLocalRef profilerOutputDir(m_env.GetObjectArrayElement(args, 5));
 
 	DEBUG_WRITE("Initializing Telerik NativeScript");
 
@@ -360,16 +362,28 @@ Isolate* Runtime::PrepareV8Runtime(const string& filesPath, jstring packageName,
 
 		m_startupData = new StartupData();
 
-		auto snapshotPath = filesPath + "/internal/snapshot.blob";
-		if( File::Exists(snapshotPath))
+		string snapshotPath;
+		bool saveSnapshot = true;
+		// we have a precompiled snapshot blob provided - try to load it directly
+		if (Constants::V8_HEAP_SNAPSHOT_BLOB.size() > 0)
+		{
+			snapshotPath = Constants::V8_HEAP_SNAPSHOT_BLOB;
+			saveSnapshot = false;
+		}
+		else
+		{
+			snapshotPath = filesPath + "/internal/snapshot.blob";
+		}
+
+		if (File::Exists(snapshotPath))
 		{
 			int length;
 			m_startupData->data = reinterpret_cast<char*>(File::ReadBinary(snapshotPath, length));
 			m_startupData->raw_size = length;
 
 			DEBUG_WRITE_FORCE("Snapshot read %s (%dB).", snapshotPath.c_str(), length);
 		}
-		else
+		else if(saveSnapshot)
 		{
 			// check for custom script to include in the snapshot
 			if(Constants::V8_HEAP_SNAPSHOT_SCRIPT.size() > 0 && File::Exists(Constants::V8_HEAP_SNAPSHOT_SCRIPT))

src/src/com/tns/V8Config.java

@@ -1,15 +1,20 @@
 package com.tns;
 
 import java.io.File;
+
 import org.json.JSONObject;
 
+import android.os.Build;
+
 class V8Config
 {
 	private static final String AndroidKey = "android";
 	private static final String V8FlagsKey = "v8Flags";
 	private static final String CodeCacheKey = "codeCache";
 	private static final String HeapSnapshotKey = "heapSnapshot";
 	private static final String HeapSnapshotScriptKey = "heapSnapshotScript";
+	private static final String HeapSnapshotBlobKey = "heapSnapshotBlob";
+	private static final String SnapshotFile = "snapshot.blob";
 	private static final String ProfilerOutputDirKey = "profilerOutputDir";
 
 	public static Object[] fromPackageJSON(File appDir)
@@ -45,9 +50,21 @@ public static Object[] fromPackageJSON(File appDir)
 					String value = androidObject.getString(HeapSnapshotScriptKey);
 					result[3] = FileSystem.resolveRelativePath(appDir.getPath(), value, appDir + "/app/");
 				}
+				if(androidObject.has(HeapSnapshotBlobKey))
+				{
+					String value = androidObject.getString(HeapSnapshotBlobKey);
+					String path = FileSystem.resolveRelativePath(appDir.getPath(), value, appDir + "/app/");
+					File dir = new File(path);
+					if(dir.exists() && dir.isDirectory()) 
+					{
+						// this path is expected to be a directory, containing three sub-directories: armeabi-v7a, x86 and arm64-v8a 
+						path = path + "/" + Build.CPU_ABI + "/" + SnapshotFile;
+						result[4] = path;
+					}
+				}
 				if(androidObject.has(ProfilerOutputDirKey))
 				{
-					result[4] = androidObject.getString(ProfilerOutputDirKey);
+					result[5] = androidObject.getString(ProfilerOutputDirKey);
 				}
 			}
 		}
@@ -70,6 +87,8 @@ private static Object[] makeDefaultOptions()
 			false,
 			// arbitrary script to be included in the snapshot
 			"",
+			// a binary file containing an already saved snapshot
+			"",
 			// V8 profiler output directory
 			""
 		};