lukechilds
/
node
mirror of https://github.com/lukechilds/node.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

src,tools: speed up startup by 2.5% 

Use zero-copy external string resources for storing the built-in JS
source code.  Saves a few hundred kilobyte of memory and consistently
speeds up `benchmark/misc/startup.js` by 2.5%.

Everything old is new again!  Commit 74954ce ("Add string class that
uses ExternalAsciiStringResource.") from 2011 did the same thing but
I removed that in 2013 in commit 34b0a36 ("src: don't use NewExternal()
with unaligned strings") because of a limitation in the V8 API.

V8 no longer requires that strings are aligned if they are one-byte
strings so it should be safe to re-enable external strings again.

PR-URL: https://github.com/nodejs/node/pull/5458
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Robert Jefe Lindstaedt <robert.lindstaedt@gmail.com>
v6
Ben Noordhuis 9 years ago
parent
2a456162b6
commit
e4290dec2d
2 changed files with 62 additions and 151 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 47
      src/node_javascript.cc
  2. 164
      tools/js2c.py

47
src/node_javascript.cc
View File

@ -6,33 +6,46 @@
namespace node {
using v8::HandleScope;
using v8::Local;
using v8::NewStringType;
using v8::Object;
using v8::String;
// id##_data is defined in node_natives.h.
#define V(id) \
static struct : public String::ExternalOneByteStringResource { \
const char* data() const override { \
return reinterpret_cast<const char*>(id##_data); \
} \
size_t length() const override { return sizeof(id##_data); } \
void Dispose() override { /* Default calls `delete this`. */ } \
} id##_external_data;
NODE_NATIVES_MAP(V)
#undef V
Local<String> MainSource(Environment* env) {
return String::NewFromUtf8(
auto maybe_string =
String::NewExternalOneByte(
env->isolate(),
reinterpret_cast<const char*>(internal_bootstrap_node_native),
NewStringType::kNormal,
sizeof(internal_bootstrap_node_native)).ToLocalChecked();
&internal_bootstrap_node_external_data);
return maybe_string.ToLocalChecked();
}
void DefineJavaScript(Environment* env, Local<Object> target) {
HandleScope scope(env->isolate());
for (auto native : natives) {
if (native.source != internal_bootstrap_node_native) {
Local<String> name = String::NewFromUtf8(env->isolate(), native.name);
Local<String> source =
String::NewFromUtf8(
env->isolate(), reinterpret_cast<const char*>(native.source),
NewStringType::kNormal, native.source_len).ToLocalChecked();
target->Set(name, source);
}
}
auto context = env->context();
#define V(id) \
do { \
auto key = \
String::NewFromOneByte( \
env->isolate(), id##_name, NewStringType::kNormal, \
sizeof(id##_name)).ToLocalChecked(); \
auto value = \
String::NewExternalOneByte( \
env->isolate(), &id##_external_data).ToLocalChecked(); \
CHECK(target->Set(context, key, value).FromJust()); \
} while (0);
NODE_NATIVES_MAP(V)
#undef V
}
} // namespace node

164
tools/js2c.py
View File

@ -37,8 +37,11 @@ import sys
import string
def ToCArray(filename, lines):
return ','.join(str(ord(c)) for c in lines)
def ToCString(contents):
step = 20
slices = (contents[i:i+step] for i in xrange(0, len(contents), step))
slices = map(lambda s: ','.join(str(ord(c)) for c in s), slices)
return ',\n'.join(slices)
def ReadFile(filename):
@ -61,21 +64,6 @@ def ReadLines(filename):
return result
def LoadConfigFrom(name):
import ConfigParser
config = ConfigParser.ConfigParser()
config.read(name)
return config
def ParseValue(string):
string = string.strip()
if string.startswith('[') and string.endswith(']'):
return string.lstrip('[').rstrip(']').split()
else:
return string
def ExpandConstants(lines, constants):
for key, value in constants.items():
lines = lines.replace(key, str(value))
@ -174,53 +162,37 @@ def ReadMacros(lines):
HEADER_TEMPLATE = """\
#ifndef node_natives_h
#define node_natives_h
namespace node {
#ifndef NODE_NATIVES_H_
#define NODE_NATIVES_H_
%(source_lines)s\
#include <stdint.h>
struct _native {
const char* name;
const unsigned char* source;
size_t source_len;
};
#define NODE_NATIVES_MAP(V) \\
{node_natives_map}
static const struct _native natives[] = { %(native_lines)s };
}
#endif
"""
NATIVE_DECLARATION = """\
{ "%(id)s", %(escaped_id)s_native, sizeof(%(escaped_id)s_native) },
"""
namespace node {{
{sources}
}} // namespace node
SOURCE_DECLARATION = """\
const unsigned char %(escaped_id)s_native[] = { %(data)s };
#endif // NODE_NATIVES_H_
"""
GET_DELAY_INDEX_CASE = """\
if (strcmp(name, "%(id)s") == 0) return %(i)i;
NODE_NATIVES_MAP = """\
V({escaped_id}) \\
"""
GET_DELAY_SCRIPT_SOURCE_CASE = """\
if (index == %(i)i) return Vector<const char>(%(id)s, %(length)i);
SOURCES = """\
static const uint8_t {escaped_id}_name[] = {{
{name}}};
static const uint8_t {escaped_id}_data[] = {{
{data}}};
"""
GET_DELAY_SCRIPT_NAME_CASE = """\
if (index == %(i)i) return Vector<const char>("%(name)s", %(length)i);
"""
def JS2C(source, target):
ids = []
delay_ids = []
modules = []
# Locate the macros file name.
consts = {}
macros = {}
macro_lines = []
@ -235,18 +207,14 @@ def JS2C(source, target):
(consts, macros) = ReadMacros(macro_lines)
# Build source code lines
source_lines = [ ]
source_lines_empty = []
native_lines = []
node_natives_map = []
sources = []
for s in modules:
delay = str(s).endswith('-delay.js')
lines = ReadFile(str(s))
lines = ExpandConstants(lines, consts)
lines = ExpandMacros(lines, macros)
data = ToCArray(s, lines)
data = ToCString(lines)
# On Windows, "./foo.bar" in the .gyp file is passed as "foo.bar"
# so don't assume there is always a slash in the file path.
@ -258,87 +226,17 @@ def JS2C(source, target):
if '.' in id:
id = id.split('.', 1)[0]
if delay: id = id[:-6]
if delay:
delay_ids.append((id, len(lines)))
else:
ids.append((id, len(lines)))
name = ToCString(id)
escaped_id = id.replace('-', '_').replace('/', '_')
source_lines.append(SOURCE_DECLARATION % {
'id': id,
'escaped_id': escaped_id,
'data': data
})
source_lines_empty.append(SOURCE_DECLARATION % {
'id': id,
'escaped_id': escaped_id,
'data': 0
})
native_lines.append(NATIVE_DECLARATION % {
'id': id,
'escaped_id': escaped_id
})
# Build delay support functions
get_index_cases = [ ]
get_script_source_cases = [ ]
get_script_name_cases = [ ]
i = 0
for (id, length) in delay_ids:
native_name = "native %s.js" % id
get_index_cases.append(GET_DELAY_INDEX_CASE % { 'id': id, 'i': i })
get_script_source_cases.append(GET_DELAY_SCRIPT_SOURCE_CASE % {
'id': id,
'length': length,
'i': i
})
get_script_name_cases.append(GET_DELAY_SCRIPT_NAME_CASE % {
'name': native_name,
'length': len(native_name),
'i': i
});
i = i + 1
for (id, length) in ids:
native_name = "native %s.js" % id
get_index_cases.append(GET_DELAY_INDEX_CASE % { 'id': id, 'i': i })
get_script_source_cases.append(GET_DELAY_SCRIPT_SOURCE_CASE % {
'id': id,
'length': length,
'i': i
})
get_script_name_cases.append(GET_DELAY_SCRIPT_NAME_CASE % {
'name': native_name,
'length': len(native_name),
'i': i
});
i = i + 1
node_natives_map.append(NODE_NATIVES_MAP.format(**locals()))
sources.append(SOURCES.format(**locals()))
node_natives_map = ''.join(node_natives_map)
sources = ''.join(sources)
# Emit result
output = open(str(target[0]), "w")
output.write(HEADER_TEMPLATE % {
'builtin_count': len(ids) + len(delay_ids),
'delay_count': len(delay_ids),
'source_lines': "\n".join(source_lines),
'native_lines': "\n".join(native_lines),
'get_index_cases': "".join(get_index_cases),
'get_script_source_cases': "".join(get_script_source_cases),
'get_script_name_cases': "".join(get_script_name_cases)
})
output.close()
if len(target) > 1:
output = open(str(target[1]), "w")
output.write(HEADER_TEMPLATE % {
'builtin_count': len(ids) + len(delay_ids),
'delay_count': len(delay_ids),
'source_lines': "\n".join(source_lines_empty),
'get_index_cases': "".join(get_index_cases),
'get_script_source_cases': "".join(get_script_source_cases),
'get_script_name_cases': "".join(get_script_name_cases)
})
output.write(HEADER_TEMPLATE.format(**locals()))
output.close()
def main():

Write Preview
Loading…
Cancel
Save