VM: Precompiled rodata snapshot.

runtime/vm/snapshot.h

 // 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.
 
 #ifndef VM_SNAPSHOT_H_
 #define VM_SNAPSHOT_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
@@ skipping 206 matching lines @@
 
   static const intptr_t kHeaderSize = OS::kMaxPreferredCodeAlignment;
 
  private:
   const void* raw_memory_;  // The symbol kInstructionsSnapshot.
 
   DISALLOW_COPY_AND_ASSIGN(InstructionsSnapshot);
 };
 
 
+class DataSnapshot : ValueObject {
+ public:
+  explicit DataSnapshot(const void* raw_memory)
+    : raw_memory_(raw_memory) {
+    ASSERT(Utils::IsAligned(raw_memory, 2 * kWordSize));  // kObjectAlignment
+  }
+
+  void* data_start() {
+    return reinterpret_cast<void*>(
+        reinterpret_cast<uword>(raw_memory_) + kHeaderSize);
+  }
+
+  uword data_size() {
+    uword snapshot_size = *reinterpret_cast<const uword*>(raw_memory_);
+    return snapshot_size - kHeaderSize;
+  }
+
+  // Two word header: data length and padding for object alignment.
+  static const intptr_t kHeaderSize = 2 * kWordSize;
+
+ private:
+  const void* raw_memory_;  // The symbol kDataSnapshot.
+
+  DISALLOW_COPY_AND_ASSIGN(DataSnapshot);
+};
+
+
 class BaseReader {
  public:
   BaseReader(const uint8_t* buffer, intptr_t size) : stream_(buffer, size) {}
   // Reads raw data (for basic types).
   // sizeof(T) must be in {1,2,4,8}.
   template <typename T>
   T Read() {
     return ReadStream::Raw<sizeof(T), T>::Read(&stream_);
   }
 
@@ skipping 89 matching lines @@
  private:
   Object* reference_;
   DeserializeState state_;
   bool defer_canonicalization_;
   ZoneGrowableArray<intptr_t>* patch_records_;
 };
 
 
 class InstructionsReader : public ZoneAllocated {
  public:
-  explicit InstructionsReader(const uint8_t* buffer)
-    : buffer_(buffer) {
-    ASSERT(buffer != NULL);
-    ASSERT(Utils::IsAligned(reinterpret_cast<uword>(buffer),
+  InstructionsReader(const uint8_t* instructions_buffer,
+                     const uint8_t* data_buffer)
+    : instructions_buffer_(instructions_buffer),
+      data_buffer_(data_buffer) {
+    ASSERT(instructions_buffer != NULL);
+    ASSERT(data_buffer != NULL);
+    ASSERT(Utils::IsAligned(reinterpret_cast<uword>(instructions_buffer),
                             OS::PreferredCodeAlignment()));
   }
 
   RawInstructions* GetInstructionsAt(int32_t offset, uword expected_tags);
+  RawObject* GetObjectAt(int32_t offset);
 
  private:
-  const uint8_t* buffer_;
+  const uint8_t* instructions_buffer_;
+  const uint8_t* data_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(InstructionsReader);
 };
 
 
 // Reads a snapshot into objects.
 class SnapshotReader : public BaseReader {
  public:
   Thread* thread() const { return thread_; }
   Zone* zone() const { return zone_; }
@@ skipping 89 matching lines @@
   RawUnhandledException* NewUnhandledException();
   RawObject* NewInteger(int64_t value);
   RawStacktrace* NewStacktrace();
   RawWeakProperty* NewWeakProperty();
   RawJSRegExp* NewJSRegExp();
 
   RawInstructions* GetInstructionsAt(int32_t offset, uword expected_tags) {
     return instructions_reader_->GetInstructionsAt(offset, expected_tags);
   }
 
+  RawObject* GetObjectAt(int32_t offset) {
+    return instructions_reader_->GetObjectAt(offset);
+  }
+
   const uint8_t* instructions_buffer_;
+  const uint8_t* data_buffer_;
 
  protected:
   SnapshotReader(const uint8_t* buffer,
                  intptr_t size,
                  const uint8_t* instructions_buffer,
+                 const uint8_t* data_buffer,
                  Snapshot::Kind kind,
                  ZoneGrowableArray<BackRefNode>* backward_references,
                  Thread* thread);
   ~SnapshotReader() { }
 
   ZoneGrowableArray<BackRefNode>* GetBackwardReferenceTable() const {
     return backward_references_;
   }
   void ResetBackwardReferenceTable() { backward_references_ = NULL; }
   PageSpace* old_space() const { return old_space_; }
@@ skipping 124 matching lines @@
   friend class WeakProperty;
   DISALLOW_COPY_AND_ASSIGN(SnapshotReader);
 };
 
 
 class VmIsolateSnapshotReader : public SnapshotReader {
  public:
   VmIsolateSnapshotReader(const uint8_t* buffer,
                           intptr_t size,
                           const uint8_t* instructions_buffer,
+                          const uint8_t* data_buffer,
                           Thread* thread);
   ~VmIsolateSnapshotReader();
 
   RawApiError* ReadVmIsolateSnapshot();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(VmIsolateSnapshotReader);
 };
 
 
 class IsolateSnapshotReader : public SnapshotReader {
  public:
   IsolateSnapshotReader(const uint8_t* buffer,
                         intptr_t size,
                         const uint8_t* instructions_buffer,
+                        const uint8_t* data_buffer,
                         Thread* thread);
   ~IsolateSnapshotReader();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(IsolateSnapshotReader);
 };
 
 
 class ScriptSnapshotReader : public SnapshotReader {
  public:
@@ skipping 168 matching lines @@
 };
 
 
 class InstructionsWriter : public ZoneAllocated {
  public:
   InstructionsWriter(uint8_t** buffer,
                      ReAlloc alloc,
                      intptr_t initial_size)
     : stream_(buffer, alloc, initial_size),
       next_offset_(InstructionsSnapshot::kHeaderSize),
+      next_object_offset_(DataSnapshot::kHeaderSize),
       binary_size_(0),
-      instructions_() {
+      instructions_(),
+      objects_() {
     ASSERT(buffer != NULL);
     ASSERT(alloc != NULL);
   }
 
   // Size of the snapshot (assembly code).
   intptr_t BytesWritten() const { return stream_.bytes_written(); }
 
   intptr_t binary_size() { return binary_size_; }
 
   int32_t GetOffsetFor(RawInstructions* instructions);
 
+  int32_t GetObjectOffsetFor(RawObject* raw_object);
+
   void SetInstructionsCode(RawInstructions* insns, RawCode* code) {
     for (intptr_t i = 0; i < instructions_.length(); i++) {
       if (instructions_[i].raw_insns_ == insns) {
         instructions_[i].raw_code_ = code;
         return;
       }
     }
     UNREACHABLE();
   }
 
   void WriteAssembly();
 
  private:
   struct InstructionsData {
     explicit InstructionsData(RawInstructions* insns)
         : raw_insns_(insns), raw_code_(NULL) { }
 
     union {
       RawInstructions* raw_insns_;
       const Instructions* insns_;
     };
     union {
       RawCode* raw_code_;
       const Code* code_;
     };
   };
 
+  struct ObjectData {
+    explicit ObjectData(RawObject* raw_obj)
+        : raw_obj_(raw_obj) { }
+
+    union {
+      RawObject* raw_obj_;
+      const Object* obj_;
+    };
+  };
+
   void WriteWordLiteral(uword value) {
     // Padding is helpful for comparing the .S with --disassemble.
 #if defined(ARCH_IS_64_BIT)
     stream_.Print(".quad 0x%0.16" Px "\n", value);
 #else
     stream_.Print(".long 0x%0.8" Px "\n", value);
 #endif
     binary_size_ += sizeof(value);
   }
 
   WriteStream stream_;
   intptr_t next_offset_;
+  intptr_t next_object_offset_;
   intptr_t binary_size_;
   GrowableArray<InstructionsData> instructions_;
+  GrowableArray<ObjectData> objects_;
 
   DISALLOW_COPY_AND_ASSIGN(InstructionsWriter);
 };
 
 
 class SnapshotWriter : public BaseWriter {
  protected:
   SnapshotWriter(Snapshot::Kind kind,
                  Thread* thread,
                  uint8_t** buffer,
@@ skipping 35 matching lines @@
 
   // Write a version string for the snapshot.
   void WriteVersion();
 
   static intptr_t FirstObjectId();
 
   int32_t GetInstructionsId(RawInstructions* instructions) {
     return instructions_writer_->GetOffsetFor(instructions);
   }
 
+  int32_t GetObjectId(RawObject* raw) {
+    return instructions_writer_->GetObjectOffsetFor(raw);
+  }
+
   void SetInstructionsCode(RawInstructions* instructions, RawCode* code) {
     return instructions_writer_->SetInstructionsCode(instructions, code);
   }
 
   void WriteFunctionId(RawFunction* func, bool owner_is_class);
 
  protected:
   bool CheckAndWritePredefinedObject(RawObject* raw);
   bool HandleVMIsolateObject(RawObject* raw);
 
@@ skipping 200 matching lines @@
  private:
   SnapshotWriter* writer_;
   bool as_references_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_