Revision: 4400
Author: [email protected]
Date: Tue Apr 13 10:00:33 2010
Log: Expose a hint which communicates that string might be written many
times.
Review URL: http://codereview.chromium.org/1609021
http://code.google.com/p/v8/source/detail?r=4400
Modified:
/branches/bleeding_edge/include/v8.h
/branches/bleeding_edge/src/api.cc
/branches/bleeding_edge/test/cctest/test-strings.cc
=======================================
--- /branches/bleeding_edge/include/v8.h Thu Apr 8 11:23:10 2010
+++ /branches/bleeding_edge/include/v8.h Tue Apr 13 10:00:33 2010
@@ -859,18 +859,23 @@
* \return The number of bytes copied to the buffer
* excluding the NULL terminator.
*/
- int Write(uint16_t* buffer, int start = 0, int length = -1) const; //
UTF-16
- int WriteAscii(char* buffer, int start = 0, int length = -1) const; //
ASCII
+ enum WriteHints {
+ NO_HINTS = 0,
+ HINT_MANY_WRITES_EXPECTED = 1
+ };
+
+ int Write(uint16_t* buffer,
+ int start = 0,
+ int length = -1,
+ WriteHints hints = NO_HINTS) const; // UTF-16
+ int WriteAscii(char* buffer,
+ int start = 0,
+ int length = -1,
+ WriteHints hints = NO_HINTS) const; // ASCII
int WriteUtf8(char* buffer,
int length = -1,
- int* nchars_ref = NULL) const; // UTF-8
-
- /**
- * Flatten internal memory. Operations on the string tend to run faster
- * after flattening especially if the string is a concatenation of many
- * others.
- */
- void Flatten();
+ int* nchars_ref = NULL,
+ WriteHints hints = NO_HINTS) const; // UTF-8
/**
* A zero length string.
=======================================
--- /branches/bleeding_edge/src/api.cc Thu Apr 8 11:23:10 2010
+++ /branches/bleeding_edge/src/api.cc Tue Apr 13 10:00:33 2010
@@ -2641,12 +2641,20 @@
}
-int String::WriteUtf8(char* buffer, int capacity, int* nchars_ref) const {
+int String::WriteUtf8(char* buffer,
+ int capacity,
+ int* nchars_ref,
+ WriteHints hints) const {
if (IsDeadCheck("v8::String::WriteUtf8()")) return 0;
LOG_API("String::WriteUtf8");
ENTER_V8;
i::Handle<i::String> str = Utils::OpenHandle(this);
StringTracker::RecordWrite(str);
+ if (hints & HINT_MANY_WRITES_EXPECTED) {
+ // Flatten the string for efficiency. This applies whether we are
+ // using StringInputBuffer or Get(i) to access the characters.
+ str->TryFlatten();
+ }
write_input_buffer.Reset(0, *str);
int len = str->length();
// Encode the first K - 3 bytes directly into the buffer since we
@@ -2688,16 +2696,21 @@
}
-int String::WriteAscii(char* buffer, int start, int length) const {
+int String::WriteAscii(char* buffer,
+ int start,
+ int length,
+ WriteHints hints) const {
if (IsDeadCheck("v8::String::WriteAscii()")) return 0;
LOG_API("String::WriteAscii");
ENTER_V8;
ASSERT(start >= 0 && length >= -1);
i::Handle<i::String> str = Utils::OpenHandle(this);
StringTracker::RecordWrite(str);
- // Flatten the string for efficiency. This applies whether we are
- // using StringInputBuffer or Get(i) to access the characters.
- str->TryFlatten();
+ if (hints & HINT_MANY_WRITES_EXPECTED) {
+ // Flatten the string for efficiency. This applies whether we are
+ // using StringInputBuffer or Get(i) to access the characters.
+ str->TryFlatten();
+ }
int end = length;
if ( (length == -1) || (length > str->length() - start) )
end = str->length() - start;
@@ -2715,13 +2728,21 @@
}
-int String::Write(uint16_t* buffer, int start, int length) const {
+int String::Write(uint16_t* buffer,
+ int start,
+ int length,
+ WriteHints hints) const {
if (IsDeadCheck("v8::String::Write()")) return 0;
LOG_API("String::Write");
ENTER_V8;
ASSERT(start >= 0 && length >= -1);
i::Handle<i::String> str = Utils::OpenHandle(this);
StringTracker::RecordWrite(str);
+ if (hints & HINT_MANY_WRITES_EXPECTED) {
+ // Flatten the string for efficiency. This applies whether we are
+ // using StringInputBuffer or Get(i) to access the characters.
+ str->TryFlatten();
+ }
int end = length;
if ( (length == -1) || (length > str->length() - start) )
end = str->length() - start;
@@ -2731,13 +2752,6 @@
buffer[end] = '\0';
return end;
}
-
-
-void v8::String::Flatten() {
- if (IsDeadCheck("v8::String::Flatten()")) return;
- i::Handle<i::String> str = Utils::OpenHandle(this);
- i::FlattenString(str);
-}
bool v8::String::IsExternal() const {
=======================================
--- /branches/bleeding_edge/test/cctest/test-strings.cc Thu Apr 8 11:23:10
2010
+++ /branches/bleeding_edge/test/cctest/test-strings.cc Tue Apr 13 10:00:33
2010
@@ -345,38 +345,6 @@
CHECK_EQ(kNoChar, buffer[j]);
}
}
-
-
-TEST(StringConcatFlatten) {
- InitializeVM();
- v8::HandleScope handle_scope;
-
- const char* stringA = "0123456789";
- const char* stringB = "ABCDEFGHIJ";
-
- v8::Local<v8::String> a = v8::String::New(stringA);
- v8::Local<v8::String> b = v8::String::New(stringB);
-
- v8::Local<v8::String> cons = v8::String::Concat(a, b);
-
- i::Handle<i::String> str = v8::Utils::OpenHandle(*cons);
- CHECK(!str->IsFlat());
-
- cons->Flatten();
-
- CHECK(str->IsFlat());
-
- char buffer[21];
- cons->WriteUtf8(buffer);
-
- for (int i = 0; i < 10; i++) {
- CHECK_EQ(stringA[i], buffer[i]);
- }
-
- for (int i = 0; i < 10; i++) {
- CHECK_EQ(stringB[i], buffer[i + 10]);
- }
-}
TEST(ExternalShortStringAdd) {
--
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