From 5b7c22f37a08b77ef1c79a7cdd4372ce2fc07de9 Mon Sep 17 00:00:00 2001
From: nik <andrew.tupitsin@gmail.com>
Date: Sun, 30 Mar 2014 16:56:26 -0300
Subject: [PATCH] inflate/deflate wrappers now call onData only if output
 buffer is full or input reached end & add tests for small input chunks

---
 lib/deflate.js | 15 ++++++------
 lib/inflate.js | 18 ++++++++------
 test/chunks.js | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+), 16 deletions(-)
 create mode 100644 test/chunks.js

diff --git a/lib/deflate.js b/lib/deflate.js
index 97a18f4..d6b7604 100644
--- a/lib/deflate.js
+++ b/lib/deflate.js
@@ -182,11 +182,14 @@ Deflate.prototype.push = function(data, mode) {
   strm.next_in = data;
   strm.next_in_index = 0;
   strm.avail_in = strm.next_in.length;
-  strm.next_out = new utils.Buf8(chunkSize);
+  strm.avail_out = 0;
 
   do {
-    strm.avail_out = this.options.chunkSize;
-    strm.next_out_index = 0;
+    if (strm.avail_out === 0) {
+      strm.next_out = new utils.Buf8(chunkSize);
+      strm.next_out_index = 0;
+      strm.avail_out = chunkSize;
+    }
     status = zlib_deflate.deflate(strm, _mode);    /* no bad return value */
 
     if (status !== Z_STREAM_END && status !== Z_OK) {
@@ -194,12 +197,8 @@ Deflate.prototype.push = function(data, mode) {
       this.ended = true;
       return false;
     }
-    if(strm.next_out_index) {
+    if (strm.avail_out === 0 || strm.avail_in === 0) {
       this.onData(utils.shrinkBuf(strm.next_out, strm.next_out_index));
-      // Allocate buffer for next chunk, if not last
-      if (strm.avail_in > 0 || strm.avail_out === 0) {
-        strm.next_out = new utils.Buf8(this.options.chunkSize);
-      }
     }
   } while (strm.avail_in > 0 || strm.avail_out === 0);
 
diff --git a/lib/inflate.js b/lib/inflate.js
index af37e03..25195a0 100644
--- a/lib/inflate.js
+++ b/lib/inflate.js
@@ -176,11 +176,15 @@ Inflate.prototype.push = function(data, mode) {
   strm.next_in = data;
   strm.next_in_index = 0;
   strm.avail_in = strm.next_in.length;
-  strm.next_out = new utils.Buf8(chunkSize);
+  strm.avail_out = 0;
 
   do {
-    strm.avail_out = this.options.chunkSize;
-    strm.next_out_index = 0;
+    if (strm.avail_out === 0) {
+      strm.next_out = new utils.Buf8(chunkSize);
+      strm.next_out_index = 0;
+      strm.avail_out = chunkSize;
+    }
+
     status = zlib_inflate.inflate(strm, _mode);    /* no bad return value */
 
     if (status !== c.Z_STREAM_END && status !== c.Z_OK) {
@@ -188,11 +192,9 @@ Inflate.prototype.push = function(data, mode) {
       this.ended = true;
       return false;
     }
-    if(strm.next_out_index) {
-      this.onData(utils.shrinkBuf(strm.next_out, strm.next_out_index));
-      // Allocate buffer for next chunk, if not last
-      if (strm.avail_in > 0 || strm.avail_out === 0) {
-        strm.next_out = new utils.Buf8(this.options.chunkSize);
+    if (strm.next_out_index) {
+      if (strm.avail_out === 0 || strm.avail_in === 0) {
+        this.onData(utils.shrinkBuf(strm.next_out, strm.next_out_index));
       }
     }
   } while (strm.avail_in > 0 || strm.avail_out === 0);
diff --git a/test/chunks.js b/test/chunks.js
new file mode 100644
index 0000000..8897c68
--- /dev/null
+++ b/test/chunks.js
@@ -0,0 +1,66 @@
+/*global describe, it*/
+
+
+'use strict';
+
+
+var assert = require('assert');
+
+var helpers = require('./helpers');
+
+var pako_utils = require('../lib/zlib/utils');
+var pako = require('../index');
+
+function randomBuf(size) {
+  var buf = pako_utils.Buf8(size);
+  for (var i = 0; i < size; i++) {
+    buf[i] = Math.round(Math.random() * 256);
+  }
+  return buf;
+}
+
+function testChunk(buf, expected, packer, chunkSize) {
+  var i, _in, count, pos, size;
+
+  count = Math.ceil(buf.length / chunkSize);
+  pos = 0;
+  for (i = 0; i < count; i++) {
+    size = (buf.length - pos) < chunkSize ? buf.length - pos : chunkSize;
+    _in = new pako_utils.Buf8(size);
+    pako_utils.arraySet(_in, buf, pos, size, 0);
+    packer.push(_in, i === count - 1);
+    pos += chunkSize;
+  }
+
+  assert(!packer.err, 'Packer error: ' + packer.err);
+
+  assert(helpers.cmpBuf(packer.result, expected), 'Result is different');
+}
+
+describe('Small input chunks', function () {
+
+  it('deflate 100b by 1b chunk', function () {
+    var buf = randomBuf(100);
+    var deflated = pako.deflate(buf);
+    testChunk(buf, deflated, new pako.Deflate(), 1);
+  });
+
+  it('deflate 8000b by 10b chunk', function () {
+    var buf = randomBuf(8000);
+    var deflated = pako.deflate(buf);
+    testChunk(buf, deflated, new pako.Deflate(), 10);
+  });
+
+  it('inflate 100b result by 1b chunk', function () {
+    var buf = randomBuf(100);
+    var deflated = pako.deflate(buf);
+    testChunk(deflated, buf, new pako.Inflate(), 1);
+  });
+
+  it('inflate 8000b result by 10b chunk', function () {
+    var buf = randomBuf(8000);
+    var deflated = pako.deflate(buf);
+    testChunk(deflated, buf, new pako.Inflate(), 10);
+  });
+
+});
\ No newline at end of file