AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

Make count-line-ends use StringSearch and only iterate over the source once.

Browse Source 
Review URL: http://codereview.chromium.org/5121007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5850 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
lrn@chromium.org 2010-11-18 10:42:22 +00:00
parent 051f314a99
commit 80ace73cb8
1 changed files with 37 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
src/handles.cc
View File

@ -37,6 +37,7 @@
#include "global-handles.h"
#include "natives.h"
#include "runtime.h"
#include "string-search.h"
#include "stub-cache.h"
namespace v8 {
@ -508,43 +509,50 @@ void InitScriptLineEnds(Handle<Script> script) {
}
Handle<FixedArray> CalculateLineEnds(Handle<String> src,
bool with_imaginary_last_new_line) {
const int src_len = src->length();
Handle<String> new_line = Factory::NewStringFromAscii(CStrVector("\n"));
template <typename SourceChar>
static void CalculateLineEnds(List<int>* line_ends,
Vector<const SourceChar> src,
bool with_last_line) {
const int src_len = src.length();
StringSearch<char, SourceChar> search(CStrVector("\n"));
// Pass 1: Identify line count.
int line_count = 0;
// Find and record line ends.
int position = 0;
while (position != -1 && position < src_len) {
position = Runtime::StringMatch(src, new_line, position);
position = search.Search(src, position);
if (position != -1) {
line_ends->Add(position);
position++;
}
if (position != -1) {
line_count++;
} else if (with_imaginary_last_new_line) {
} else if (with_last_line) {
// Even if the last line misses a line end, it is counted.
line_count++;
line_ends->Add(src_len);
return;
}
}
}
// Pass 2: Fill in line ends positions
Handle<FixedArray> CalculateLineEnds(Handle<String> src,
bool with_last_line) {
src = FlattenGetString(src);
// Rough estimate of line count based on a roughly estimated average
// length of (unpacked) code.
int line_count_estimate = src->length() >> 4;
List<int> line_ends(line_count_estimate);
{
AssertNoAllocation no_heap_allocation; // ensure vectors stay valid.
// Dispatch on type of strings.
if (src->IsAsciiRepresentation()) {
CalculateLineEnds(&line_ends, src->ToAsciiVector(), with_last_line);
} else {
CalculateLineEnds(&line_ends, src->ToUC16Vector(), with_last_line);
}
}
int line_count = line_ends.length();
Handle<FixedArray> array = Factory::NewFixedArray(line_count);
int array_index = 0;
position = 0;
while (position != -1 && position < src_len) {
position = Runtime::StringMatch(src, new_line, position);
if (position != -1) {
array->set(array_index++, Smi::FromInt(position++));
} else if (with_imaginary_last_new_line) {
// If the script does not end with a line ending add the final end
// position as just past the last line ending.
array->set(array_index++, Smi::FromInt(src_len));
}
for (int i = 0; i < line_count; i++) {
array->set(i, Smi::FromInt(line_ends[i]));
}
ASSERT(array_index == line_count);
return array;
}
@ -556,11 +564,11 @@ int GetScriptLineNumber(Handle<Script> script, int code_pos) {
FixedArray* line_ends_array = FixedArray::cast(script->line_ends());
const int line_ends_len = line_ends_array->length();
if (!line_ends_len)
return -1;
if (!line_ends_len) return -1;
if ((Smi::cast(line_ends_array->get(0)))->value() >= code_pos)
if ((Smi::cast(line_ends_array->get(0)))->value() >= code_pos) {
return script->line_offset()->value();
}
int left = 0;
int right = line_ends_len;