Restructure the Kernel string table.

runtime/vm/kernel_binary.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.
 #if !defined(DART_PRECOMPILED_RUNTIME)
 
 #include "vm/kernel_binary.h"
 #include "platform/globals.h"
 #include "vm/flags.h"
 #include "vm/growable_array.h"
 #include "vm/kernel.h"
@@ skipping 114 matching lines @@
 
 
 String* String::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   return Reference::ReadStringFrom(reader);
 }
 
 
 String* String::ReadFromImpl(Reader* reader) {
   TRACE_READ_OFFSET();
-  uint32_t bytes = reader->ReadUInt();
-  return new String(reader->Consume(bytes), bytes);
-}
-
-void StringTable::ReadFrom(Reader* reader) {
-  strings_.ReadFromStatic<StringImpl>(reader);
+  intptr_t size = reader->ReadUInt();
+  return ReadRaw(reader, size);
 }
 
 
+String* String::ReadRaw(Reader* reader, intptr_t size) {
+  return new String(reader->Consume(size), size);
+}
+
+
+void StringTable::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  // Read the table of end offsets.
+  intptr_t length = reader->ReadUInt();
+  int* end_offsets = new int[length];
+  for (intptr_t i = 0; i < length; ++i) {
+    end_offsets[i] = reader->ReadUInt();
+  }
+  // Read the UTF-8 encoded strings.
+  strings_.EnsureInitialized(length);
+  intptr_t start_offset = 0;
+  for (intptr_t i = 0; i < length; ++i) {
+    ASSERT(strings_[i] == NULL);
+    strings_[i] = String::ReadRaw(reader, end_offsets[i] - start_offset);
+    start_offset = end_offsets[i];
+  }
+  delete[] end_offsets;
+}
+
+
 void SourceTable::ReadFrom(Reader* reader) {
   size_ = reader->helper()->program()->source_uri_table().strings().length();
   source_code_ = new String*[size_];
   line_starts_ = new intptr_t*[size_];
   line_count_ = new intptr_t[size_];
   for (intptr_t i = 0; i < size_; ++i) {
     source_code_[i] = StringImpl::ReadFrom(reader);
     intptr_t line_count = reader->ReadUInt();
     intptr_t* line_starts = new intptr_t[line_count];
     line_count_[i] = line_count;
@@ skipping 1304 matching lines @@
 
 kernel::Program* ReadPrecompiledKernelFromBuffer(const uint8_t* buffer,
                                                  intptr_t buffer_length) {
   kernel::Reader reader(buffer, buffer_length);
   return kernel::Program::ReadFrom(&reader);
 }
 
 
 }  // namespace dart
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)