Skip to content

buffer: optimize hex parsing. #7602

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
chjj wants to merge 3 commits into from
Closed

buffer: optimize hex parsing. #7602

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
5a8b48e
buffer: optimize hex_decode.
chjj Jul 7, 2016
ae21267
buffer: fix hex parsing and add bad hex string test.
chjj Jul 8, 2016
1627283
buffer: lint for hex parsing optimization.
chjj Jul 8, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
buffer: fix hex parsing and add bad hex string test.
  • Loading branch information
@chjj
chjj committed Jul 8, 2016
commit ae2126747fb79aa879fdcecc1aa12aeca579429b
4 changes: 2 additions & 2 deletions src/string_bytes.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -143,7 +143,7 @@ const int8_t unbase64_table[256] =
};


const int8_t unhex_table[256] =
static const int8_t unhex_table[256] =
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
Expand All @@ -163,7 +163,7 @@ const int8_t unhex_table[256] =
};

#define unhex(x) \
static_cast<uint8_t>(unhex_table[static_cast<uint8_t>(x)])
static_cast<unsigned>(unhex_table[static_cast<uint8_t>(x)])


template <typename TypeName>
Expand Down
44 changes: 44 additions & 0 deletions test/parallel/test-buffer-badhex.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,44 @@
'use strict';
var common = require('../common');
var assert = require('assert');

var Buffer = require('buffer').Buffer;

@jasnell jasnell Jul 8, 2016

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

const here please


// Test hex strings and bad hex strings
{
const buf1 = Buffer.alloc(4);
assert.equal(buf1.length, 4);
assert.deepStrictEqual(buf1, new Buffer([0, 0, 0, 0]));
assert.equal(buf1.write('abcdxx', 0, 'hex'), 2);
assert.deepStrictEqual(buf1, new Buffer([0xab, 0xcd, 0x00, 0x00]));
assert.equal(buf1.toString('hex'), 'abcd0000');
assert.equal(buf1.write('abcdef01', 0, 'hex'), 4);
assert.deepStrictEqual(buf1, new Buffer([0xab, 0xcd, 0xef, 0x01]));
assert.equal(buf1.toString('hex'), 'abcdef01');

const buf2 = Buffer.from(buf1.toString('hex'), 'hex');
assert.equal(buf1.toString('hex'), buf2.toString('hex'));

const buf3 = Buffer.alloc(5);
assert.equal(buf3.write('abcdxx', 1, 'hex'), 2);
assert.equal(buf3.toString('hex'), '00abcd0000');

const buf4 = Buffer.alloc(4);
assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
assert.equal(buf4.write('xxabcd', 0, 'hex'), 0);
assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
assert.equal(buf4.write('xxab', 1, 'hex'), 0);

@addaleax addaleax Jul 8, 2016

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: assert.strictEqual is generally preferred over assert.equal, especially for comparisons with 0. :)

assert.deepStrictEqual(buf4, new Buffer([0, 0, 0, 0]));
assert.equal(buf4.write('cdxxab', 0, 'hex'), 1);
assert.deepStrictEqual(buf4, new Buffer([0xcd, 0, 0, 0]));

const buf5 = Buffer.alloc(256);
for (let i = 0; i < 256; i++)
buf5[i] = i;

const hex = buf5.toString('hex');
assert.deepStrictEqual(Buffer.from(hex, 'hex'), buf5);

const badHex = hex.slice(0, 256) + 'xx' + hex.slice(256, 510);
assert.deepStrictEqual(Buffer.from(badHex, 'hex'), buf5.slice(0, 128));
}