snappyjs - npm Package Compare versions

Comparing version 0.3.1 to 0.4.0

bower.json

 {
   "name": "snappyjs",
   "main": "./dist/snappyjs.js",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "homepage": "https://github.com/zhipeng-jia/snappyjs",
@@ -6,0 +6,0 @@ "authors": [

package.json

 {
   "name": "snappyjs",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "JavaScript implementation of Google's Snappy compression library",
@@ -8,3 +8,3 @@ "repository": "zhipeng-jia/snappyjs",
   "scripts": {
-    "test": "tap test.js"
+    "test": "standard && tap test.js"
   },
@@ -22,2 +22,3 @@ "author": "Zhipeng Jia",
     "snappy": "~4.1.1",
+    "standard": "~6.0.4",
     "tap": "~5.1.1",
@@ -28,3 +29,14 @@ "uglifyify": "~3.0.1"
     "snappy"
-  ]
+  ],
+  "standard": {
+    "ignore": [
+      "/dist/snappyjs.js",
+      "/dist/snappyjs.min.js"
+    ],
+    "globals": [
+      "FileReader",
+      "Benchmark",
+      "SnappyJS"
+    ]
+  }
 }

README.md

@@ -1,2 +0,2 @@
-# SnappyJS [![Travis CI status](https://travis-ci.org/zhipeng-jia/snappyjs.svg?branch=master)](https://travis-ci.org/zhipeng-jia/snappyjs)
+# SnappyJS [![js-standard-style](https://img.shields.io/badge/code%20style-standard-brightgreen.svg)](http://standardjs.com/) [![Travis CI status](https://travis-ci.org/zhipeng-jia/snappyjs.svg?branch=master)](https://travis-ci.org/zhipeng-jia/snappyjs)
 A pure JavaScript implementation of Google's [Snappy](https://github.com/google/snappy) compression library.
@@ -54,23 +54,30 @@
 ~~~
-Real text #1 (length 618425, byte length 1236850):
-node-snappy#compress x 170 ops/sec ±0.96% (74 runs sampled)
-snappyjs#compress x 54.34 ops/sec ±1.27% (67 runs sampled)
-node-snappy#uncompress x 461 ops/sec ±1.60% (73 runs sampled)
-snappyjs#uncompress x 164 ops/sec ±1.31% (70 runs sampled)
+Real text #1 (length 618425, byte length 618425), repeated 100 times:
+node-snappy#compress x 2.31 ops/sec ±1.47% (10 runs sampled)
+snappyjs#compress x 0.91 ops/sec ±0.92% (7 runs sampled)
+node-snappy#uncompress x 7.22 ops/sec ±4.07% (22 runs sampled)
+snappyjs#uncompress x 2.45 ops/sec ±1.53% (11 runs sampled)
 
-Real text #2 (length 3844590, byte length 7689180):
-node-snappy#compress x 42.77 ops/sec ±1.33% (54 runs sampled)
-snappyjs#compress x 17.78 ops/sec ±1.20% (46 runs sampled)
-node-snappy#uncompress x 101 ops/sec ±4.43% (61 runs sampled)
-snappyjs#uncompress x 40.93 ops/sec ±0.88% (52 runs sampled)
+Real text #2 (length 3844590, byte length 3844591), repeated 10 times:
+node-snappy#compress x 7.68 ops/sec ±2.78% (23 runs sampled)
+snappyjs#compress x 3.56 ops/sec ±1.44% (13 runs sampled)
+node-snappy#uncompress x 17.94 ops/sec ±4.71% (33 runs sampled)
+snappyjs#uncompress x 7.24 ops/sec ±2.57% (22 runs sampled)
 
-Random string (length 1000000, byte length 2000000):
-node-snappy#compress x 125 ops/sec ±1.76% (73 runs sampled)
-snappyjs#compress x 29.34 ops/sec ±2.41% (52 runs sampled)
-node-snappy#uncompress x 381 ops/sec ±3.33% (66 runs sampled)
-snappyjs#uncompress x 163 ops/sec ±1.40% (70 runs sampled)
+Random string (length 1000000, byte length 1500098), repeated 50 times:
+node-snappy#compress x 6.69 ops/sec ±5.23% (21 runs sampled)
+snappyjs#compress x 2.39 ops/sec ±2.54% (10 runs sampled)
+node-snappy#uncompress x 14.94 ops/sec ±6.90% (40 runs sampled)
+snappyjs#uncompress x 5.92 ops/sec ±4.28% (19 runs sampled)
+
+Random string (length 100, byte length 147), repeated 100000 times:
+node-snappy#compress x 4.17 ops/sec ±2.96% (15 runs sampled)
+snappyjs#compress x 5.45 ops/sec ±1.51% (18 runs sampled)
+node-snappy#uncompress x 4.39 ops/sec ±3.83% (15 runs sampled)
+snappyjs#uncompress x 14.01 ops/sec ±2.06% (38 runs sampled)
 ~~~
 
-From the result, we see that SnappyJS has 35%~40% performance of native implementation on uncompression,
-and 25%~35% performance on compression.
+From the result, we see that SnappyJS has 35%~45% performance of native implementation.
+If input size is small, SnappyJS may have better performance than `node-snappy`.
+It is because calling native function in JS is much more expensive than calling JS function.
 
@@ -77,0 +84,0 @@ ## License

snappy_compressor.js

@@ -28,10 +28,7 @@ // The MIT License (MIT)
 
-var HASH_TABLE_BITS = 14
-var HASH_TABLE_SIZE = 1 << HASH_TABLE_BITS
+var MAX_HASH_TABLE_BITS = 14
+var global_hash_tables = new Array(MAX_HASH_TABLE_BITS + 1)
 
-var HASH_FUNC_SHIFT = 32 - HASH_TABLE_BITS
-
-function hashFunc (key) {
-  var h = key * 0x1e35a7bd
-  return h >>> HASH_FUNC_SHIFT
+function hashFunc (key, hash_func_shift) {
+  return (key * 0x1e35a7bd) >>> hash_func_shift
 }
@@ -100,3 +97,15 @@
 
-function compressFragment (input, ip, input_size, output, op, hash_table) {
+function compressFragment (input, ip, input_size, output, op) {
+  var hash_table_bits = 1
+  while ((1 << hash_table_bits) <= input_size &&
+         hash_table_bits <= MAX_HASH_TABLE_BITS) {
+    hash_table_bits += 1
+  }
+  hash_table_bits -= 1
+  var hash_func_shift = 32 - hash_table_bits
+
+  if (typeof global_hash_tables[hash_table_bits] === 'undefined') {
+    global_hash_tables[hash_table_bits] = new Uint16Array(1 << hash_table_bits)
+  }
+  var hash_table = global_hash_tables[hash_table_bits]
   var i
@@ -124,3 +133,3 @@ for (i = 0; i < hash_table.length; i++) {
     ip += 1
-    next_hash = hashFunc(load32(input, ip))
+    next_hash = hashFunc(load32(input, ip), hash_func_shift)
 
@@ -140,3 +149,3 @@ while (flag) {
         }
-        next_hash = hashFunc(load32(input, next_ip))
+        next_hash = hashFunc(load32(input, next_ip), hash_func_shift)
         candidate = base_ip + hash_table[hash]
@@ -167,5 +176,5 @@ hash_table[hash] = ip - base_ip
         }
-        prev_hash = hashFunc(load32(input, ip - 1))
+        prev_hash = hashFunc(load32(input, ip - 1), hash_func_shift)
         hash_table[prev_hash] = ip - 1 - base_ip
-        cur_hash = hashFunc(load32(input, ip))
+        cur_hash = hashFunc(load32(input, ip), hash_func_shift)
         candidate = base_ip + hash_table[cur_hash]
@@ -180,3 +189,3 @@ hash_table[cur_hash] = ip - base_ip
       ip += 1
-      next_hash = hashFunc(load32(input, ip))
+      next_hash = hashFunc(load32(input, ip), hash_func_shift)
     }
@@ -206,3 +215,2 @@ }
   this.array = uncompressed
-  this.hash_table = new Uint16Array(HASH_TABLE_SIZE)
 }
@@ -221,3 +229,2 @@
 
-  var hash_table = this.hash_table
   var fragment_size
@@ -228,3 +235,3 @@
     fragment_size = Math.min(length - pos, BLOCK_SIZE)
-    out_pos = compressFragment(array, pos, fragment_size, out_buffer, out_pos, hash_table)
+    out_pos = compressFragment(array, pos, fragment_size, out_buffer, out_pos)
     pos += fragment_size
@@ -231,0 +238,0 @@ }

No alert changes

Improved metrics

Total package byte prevSize

20078

increased by5.46%

Lines of code

450

increased by1.58%

Number of lines in readme file

86

increased by8.86%

Worsened metrics

Dev dependency count

10

increased by11.11%

No dependency changes