Balance between increasing and decreasing the bufferPool

Author: Ruben Bridgewater

lib/parser.js

@@ -4,6 +4,8 @@ var ReplyError = require('./replyError')
 var bufferPool = new Buffer(32 * 1024)
 var bufferOffset = 0
 var interval = null
+var counter = 0
+var notDecreased = 0
 
 /**
  * Used for lengths and numbers only, faster perf on arrays / bulks
@@ -307,11 +309,19 @@ function concatBulkString (parser) {
  * @returns {undefined}
  */
 function decreaseBufferPool () {
-  if (bufferPool.length > 96 * 1024) {
-    // Decrease the bufferPool by 16kb
-    bufferPool = bufferPool.slice(0, bufferPool.length - 16 * 1024)
+  if (bufferPool.length > 50 * 1024) {
+    // Balance between increasing and decreasing the bufferPool
+    if (counter === 1 || notDecreased > counter * 2) {
+      // Decrease the bufferPool by 16kb by removing the first 16kb of the current pool
+      bufferPool = bufferPool.slice(16 * 1024, bufferPool.length)
+    } else {
+      notDecreased++
+      counter--
+    }
   } else {
     clearInterval(interval)
+    counter = 0
+    notDecreased = 0
     interval = null
   }
 }
@@ -330,6 +340,7 @@ function concatBuffer (parser, length) {
     // Increase the bufferPool size by three times the current needed length
     bufferPool = new Buffer(length * 3 + bufferOffset)
     bufferOffset = 0
+    counter++
     pos = 0
     if (interval === null) {
       interval = setInterval(decreaseBufferPool, 30)

test/parsers.spec.js

@@ -607,7 +607,10 @@ describe('parsers', function () {
           chunks[i] = new Buffer(bigStringArray.join(' ') + '.') // Math.pow(2, 16) chars long
         }
         var replyCount = 0
+        var replies = []
+        var jsParser = Parser.name === 'JavascriptRedisParser'
         function checkReply (reply) {
+          replies.push(reply)
           replyCount++
         }
         var parser = new Parser({
@@ -620,29 +623,35 @@ describe('parsers', function () {
         assert.strictEqual(replyCount, 0)
         parser.execute(startBigBuffer)
         for (i = 0; i < 2; i++) {
-          if (Parser.name === 'JavascriptReplyParser') {
+          if (jsParser) {
             assert.strictEqual(parser.bufferCache.length, i + 1)
           }
           parser.execute(chunks[i])
         }
         assert.strictEqual(replyCount, 1)
         parser.execute(new Buffer('\r\n'))
         assert.strictEqual(replyCount, 2)
-        parser.execute(new Buffer('+test'))
-        assert.strictEqual(replyCount, 2)
-        parser.execute(startSecondBigBuffer)
-        for (i = 0; i < 4; i++) {
-          if (Parser.name === 'JavascriptReplyParser') {
-            assert.strictEqual(parser.bufferCache.length, i + 1)
+        setTimeout(function () {
+          parser.execute(new Buffer('+test'))
+          assert.strictEqual(replyCount, 2)
+          parser.execute(startSecondBigBuffer)
+          for (i = 0; i < 4; i++) {
+            if (jsParser) {
+              assert.strictEqual(parser.bufferCache.length, i + 1)
+            }
+            parser.execute(chunks[i])
           }
-          parser.execute(chunks[i])
-        }
-        assert.strictEqual(replyCount, 3)
-        parser.execute(new Buffer('\r\n'))
-        assert.strictEqual(replyCount, 4)
+          assert.strictEqual(replyCount, 3)
+          parser.execute(new Buffer('\r\n'))
+          assert.strictEqual(replyCount, 4)
+        }, 200)
         // Delay done so the bufferPool is cleared and tested
-        // If the buffer is not cleared, the coverage is not going to be at 100%
-        setTimeout(done, 600)
+        // If the buffer is not cleared, the coverage is not going to be at 100
+        setTimeout(function () {
+          var totalBuffer = Buffer.concat(chunks).toString()
+          assert.strictEqual(replies[3].toString(), totalBuffer)
+          done()
+        }, (jsParser ? 1800 : 250))
       })
 
       it('handle big data', function () {
@@ -668,7 +677,7 @@ describe('parsers', function () {
         })
         parser.execute(startBigBuffer)
         for (i = 0; i < 64; i++) {
-          if (Parser.name === 'JavascriptReplyParser') {
+          if (Parser.name === 'JavascriptRedisParser') {
             assert.strictEqual(parser.bufferCache.length, i + 1)
           }
           parser.execute(chunks[i])
@@ -701,7 +710,7 @@ describe('parsers', function () {
         parser.execute(new Buffer('+test'))
         parser.execute(startBigBuffer)
         for (i = 0; i < 64; i++) {
-          if (Parser.name === 'JavascriptReplyParser') {
+          if (Parser.name === 'JavascriptRedisParser') {
             assert.strictEqual(parser.bufferCache.length, i + 1)
           }
           parser.execute(chunks[i])
@@ -735,7 +744,7 @@ describe('parsers', function () {
         })
         parser.execute(startBigBuffer)
         for (i = 0; i < 64; i++) {
-          if (Parser.name === 'JavascriptReplyParser') {
+          if (Parser.name === 'JavascriptRedisParser') {
             assert.strictEqual(parser.bufferCache.length, i + 1)
           }
           parser.execute(chunks[i])