Reviewers: Mikhail Naganov (Chromium), loislo, alexeif,
Description:
Switching to a custom itoa implementation reduces serialization time at
least by
the factor of 2.
Please review this at https://chromiumcodereview.appspot.com/9950146/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/profile-generator.cc
Index: src/profile-generator.cc
===================================================================
--- src/profile-generator.cc (revision 11222)
+++ src/profile-generator.cc (working copy)
@@ -3353,9 +3353,7 @@
MaybeWriteChunk();
}
}
- void AddNumber(int n) { AddNumberImpl<int>(n, "%d"); }
void AddNumber(unsigned n) { AddNumberImpl<unsigned>(n, "%u"); }
- void AddNumber(uint64_t n) { AddNumberImpl<uint64_t>(n, "%llu"); }
void Finalize() {
if (aborted_) return;
ASSERT(chunk_pos_ < chunk_size_);
@@ -3510,6 +3508,30 @@
}
+static char* itoa(int value, char* buffer) {
+ if (value < 0) {
+ *buffer = '-';
+ ++buffer;
+ value = -value;
+ }
+
+ int number_of_digits = 0;
+ int t = value;
+ do {
+ ++number_of_digits;
+ } while (t /= 10);
+
+ buffer += number_of_digits;
+ char* result = buffer;
+ do {
+ int last_digit = value % 10;
+ value /= 10;
+ *--buffer = '0' + last_digit;
+ } while (value);
+ return result;
+}
+
+
void HeapSnapshotJSONSerializer::SerializeEdge(HeapGraphEdge* edge) {
// The buffer needs space for 3 ints, 3 commas and \0
static const int kBufferSize =
@@ -3522,10 +3544,15 @@
STATIC_CHECK(sizeof(int) == sizeof(edge->type())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(edge_name_or_index)); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(GetNodeId(edge->to()))); // NOLINT
- int result = OS::SNPrintF(buffer, ",%d,%d,%d",
- edge->type(), edge_name_or_index, GetNodeId(edge->to()));
- USE(result);
- ASSERT(result != -1);
+ char* buffer_pos = buffer.start();
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(edge->type(), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(edge_name_or_index, buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(GetNodeId(edge->to()), buffer_pos);
+ *buffer_pos++ = '\0';
+ ASSERT(buffer_pos <= (buffer.start() + buffer.length()));
writer_->AddString(buffer.start());
}
@@ -3545,16 +3572,24 @@
STATIC_CHECK(sizeof(int) == sizeof(entry->retained_size())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(GetNodeId(entry->dominator()))); //
NOLINT
STATIC_CHECK(sizeof(int) == sizeof(children.length())); // NOLINT
- int result = OS::SNPrintF(buffer, "\n,%d,%d,%u,%d,%d,%d,%d",
- entry->type(),
- GetStringId(entry->name()),
- entry->id(),
- entry->self_size(),
- entry->retained_size(),
- GetNodeId(entry->dominator()),
- children.length());
- USE(result);
- ASSERT(result != -1);
+ char* buffer_pos = buffer.start();
+ *buffer_pos++ = '\n';
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(entry->type(), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(GetStringId(entry->name()), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(entry->id(), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(entry->self_size(), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(entry->retained_size(), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(GetNodeId(entry->dominator()), buffer_pos);
+ *buffer_pos++ = ',';
+ buffer_pos = itoa(children.length(), buffer_pos);
+ *buffer_pos++ = '\0';
+ ASSERT(buffer_pos <= (buffer.start() + buffer.length()));
writer_->AddString(buffer.start());
for (int i = 0; i < children.length(); ++i) {
SerializeEdge(&children[i]);
--
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