[inspector] restore provisional breakpoints smarter

src/inspector/v8-debugger-script.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/inspector/v8-debugger-script.h"
 
 #include "src/inspector/inspected-context.h"
+#include "src/inspector/search-util.h"
 #include "src/inspector/string-util.h"
 #include "src/inspector/wasm-translation.h"
 
 namespace v8_inspector {
 
 namespace {
 
 const char hexDigits[17] = "0123456789ABCDEF";
 
 void appendUnsignedAsHex(uint64_t number, String16Builder* destination) {
@@ skipping 129 matching lines @@
     m_script.Reset(m_isolate, script);
   }
 
   bool isLiveEdit() const override { return m_isLiveEdit; }
   bool isModule() const override { return m_isModule; }
 
   const String16& sourceMappingURL() const override {
     return m_sourceMappingURL;
   }
 
-  String16 source(v8::Isolate* isolate) const override {
+  String16 source() const override {
+    v8::HandleScope scope(m_isolate);
     if (!m_sourceObj.IsEmpty())
-      return toProtocolString(m_sourceObj.Get(isolate));
-    return V8DebuggerScript::source(isolate);
+      return toProtocolString(m_sourceObj.Get(m_isolate));
+    return V8DebuggerScript::source();
   }
 
   void setSourceMappingURL(const String16& sourceMappingURL) override {
     m_sourceMappingURL = sourceMappingURL;
   }
 
   void setSource(v8::Local<v8::String> source) override {
-    m_source = String16();
+    std::vector<int> empty;
+    m_lineEndings.swap(empty);
     m_sourceObj.Reset(m_isolate, source);
     m_hash = String16();
   }
 
   bool getPossibleBreakpoints(
       const v8::debug::Location& start, const v8::debug::Location& end,
       std::vector<v8::debug::Location>* locations) override {
     v8::HandleScope scope(m_isolate);
     v8::Local<v8::debug::Script> script = m_script.Get(m_isolate);
     return script->GetPossibleBreakpoints(start, end, locations);
   }
 
   void resetBlackboxedStateCache() override {
     v8::HandleScope scope(m_isolate);
     v8::debug::ResetBlackboxedStateCache(m_isolate, m_script.Get(m_isolate));
   }
 
  private:
+  void calculateLineEndings() override {
+    if (!m_lineEndings.empty()) return;
+    v8::HandleScope scope(m_isolate);
+    m_script.Get(m_isolate)->LineEnds().swap(m_lineEndings);
+  }
+
   String16 GetNameOrSourceUrl(v8::Local<v8::debug::Script> script) {
     v8::Local<v8::String> name;
     if (script->Name().ToLocal(&name) || script->SourceURL().ToLocal(&name))
       return toProtocolString(name);
     return String16();
   }
 
   String16 m_sourceMappingURL;
   v8::Global<v8::String> m_sourceObj;
   bool m_isLiveEdit = false;
@@ skipping 55 matching lines @@
     for (v8::debug::Location& loc : *locations) {
       TranslateV8LocationToProtocolLocation(m_wasmTranslation, &loc, v8ScriptId,
                                             scriptId());
     }
     return success;
   }
 
   void resetBlackboxedStateCache() override {}
 
  private:
+  void calculateLineEndings() override {

[alph, 2017/02/08 02:02:08]

ensureLineEndings?

+    if (!m_lineEndings.empty()) return;
+    String16 text = source();
+    const String16 lineEndString = "\n";
+    size_t start = 0;
+    while (start < text.length()) {
+      size_t lineEnd = text.find(lineEndString, start);

[alph, 2017/02/08 02:02:08]

nit: find(UChar) should be faster.

+      if (lineEnd == String16::kNotFound) break;
+      m_lineEndings.push_back(static_cast<int>(lineEnd));
+      start = lineEnd + 1;
+    }
+    m_lineEndings.push_back(static_cast<int>(text.length()));
+  }
+
   static const String16& emptyString() {
     static const String16 singleEmptyString;
     return singleEmptyString;
   }
 
   v8::Global<v8::debug::WasmScript> m_script;
   WasmTranslation* m_wasmTranslation;
 };
 
 }  // namespace
@@ skipping 17 matching lines @@
 V8DebuggerScript::V8DebuggerScript(v8::Isolate* isolate, String16 id,
                                    String16 url)
     : m_id(std::move(id)), m_url(std::move(url)), m_isolate(isolate) {}
 
 V8DebuggerScript::~V8DebuggerScript() {}
 
 const String16& V8DebuggerScript::sourceURL() const {
   return m_sourceURL.isEmpty() ? m_url : m_sourceURL;
 }
 
-const String16& V8DebuggerScript::hash(v8::Isolate* isolate) const {
-  if (m_hash.isEmpty()) m_hash = calculateHash(source(isolate));
+const String16& V8DebuggerScript::hash() const {
+  if (m_hash.isEmpty()) m_hash = calculateHash(source());
   DCHECK(!m_hash.isEmpty());
   return m_hash;
 }
 
 void V8DebuggerScript::setSourceURL(const String16& sourceURL) {
   m_sourceURL = sourceURL;
 }
 
+String16 V8DebuggerScript::lineAt(int lineNumberWithOffset, int maxLength) {
+  String16 sourceStr = source();
+  calculateLineEndings();
+  int lineNumber = lineNumberWithOffset - m_startLine;
+  if (lineNumber >= static_cast<int>(m_lineEndings.size()) || lineNumber < 0)

[alph, 2017/02/08 02:02:08]

{}

+    return String16();
+  size_t lineEnd = m_lineEndings[lineNumber];
+  size_t lineStart = lineNumber > 0 ? m_lineEndings[lineNumber - 1] + 1 : 0;
+  String16 line = sourceStr.substring(lineStart, lineEnd - lineStart);
+  if (line.length() && line[line.length() - 1] == '\r')

[alph, 2017/02/08 02:02:08]

{}

+    line = line.substring(0, line.length() - 1);
+  if (maxLength) line = line.substring(0, maxLength);
+  return line;
+}
+
 }  // namespace v8_inspector