util/finagle: Small changes to avoid allocations

Problem In various places we use methods that rely on Scala's implicits to enrich them. This typically at the cost of an unnecessary object allocation. There are some other simple changes to be made that avoid allocations as well. Solution Use methods that do not require allocations. Some examples: * String.nonEmpty => !String.isEmpty * String.size => String.length * StringBuilder.size => StringBuilder.length * Array.size => Array.length * Seq.empty => Nil RB_ID=630964
twitter · Apr 13, 2015 · 09d490f · 09d490f
1 parent d4595fe
commit 09d490f
Show file tree

Hide file tree

Showing 25 changed files with 126 additions and 115 deletions.
diff --git a/finagle-core/src/main/scala/com/twitter/finagle/builder/SourceTrackingMonitor.scala b/finagle-core/src/main/scala/com/twitter/finagle/builder/SourceTrackingMonitor.scala
@@ -25,7 +25,7 @@ class SourceTrackingMonitor(logger: Logger, which: String) extends Monitor {
     false
   }
 
-  private[this] def unrollCauses(exc: Throwable, res: Seq[String] = Seq()): Seq[String] = exc match {
+  private[this] def unrollCauses(exc: Throwable, res: Seq[String] = Nil): Seq[String] = exc match {
     case null => res.reverse
     case se: SourcedException => unrollCauses(se.getCause, se.serviceName +: res)
     case fail: Failure => fail.getSource(Failure.Source.Service) match {

diff --git a/finagle-core/src/main/scala/com/twitter/finagle/socks/SocksConnectHandler.scala b/finagle-core/src/main/scala/com/twitter/finagle/socks/SocksConnectHandler.scala
@@ -86,7 +86,7 @@ class SocksConnectHandler(
   private[this] def writeInit(ctx: ChannelHandlerContext) {
     val buf = ChannelBuffers.dynamicBuffer(1024)
     buf.writeByte(Version5)
-    buf.writeByte(supportedTypes.size.toByte)
+    buf.writeByte(supportedTypes.length.toByte)
     buf.writeBytes(supportedTypes)
 
     write(ctx, buf)
@@ -117,7 +117,7 @@ class SocksConnectHandler(
       case _ => // unresolved host
         buf.writeByte(HostnameIndicator)
         val hostnameBytes = addr.getHostName.getBytes(Charsets.UsAscii)
-        buf.writeByte(hostnameBytes.size)
+        buf.writeByte(hostnameBytes.length)
         buf.writeBytes(hostnameBytes)
     }
 
@@ -132,11 +132,11 @@ class SocksConnectHandler(
 
     // RFC does not specify an encoding. Assume UTF8
     val usernameBytes = username.getBytes(Charsets.Utf8)
-    buf.writeByte(usernameBytes.size.toByte)
+    buf.writeByte(usernameBytes.length.toByte)
     buf.writeBytes(usernameBytes)
 
     val passBytes = pass.getBytes(Charsets.Utf8)
-    buf.writeByte(passBytes.size.toByte)
+    buf.writeByte(passBytes.length.toByte)
     buf.writeBytes(passBytes)
 
     write(ctx, buf)

diff --git a/finagle-core/src/main/scala/com/twitter/finagle/stats/SummarizingStatsReceiver.scala b/finagle-core/src/main/scala/com/twitter/finagle/stats/SummarizingStatsReceiver.scala
@@ -8,7 +8,7 @@ package com.twitter.finagle.stats
 import com.google.common.util.concurrent.AtomicLongMap
 import com.google.common.cache.{CacheBuilder, CacheLoader}
 import scala.collection.JavaConverters._
-import scala.collection.mutable.{ArrayBuffer, SynchronizedBuffer}
+import scala.collection.mutable.ArrayBuffer
 
 class SummarizingStatsReceiver extends StatsReceiverWithCumulativeGauges {
   val repr = this
@@ -30,7 +30,7 @@ class SummarizingStatsReceiver extends StatsReceiverWithCumulativeGauges {
   }
 
   def stat(name: String*) = new Stat {
-    def add(value: Float) = SummarizingStatsReceiver.this.synchronized { 
+    def add(value: Float) = SummarizingStatsReceiver.this.synchronized {
       stats.get(name) += value
     }
   }
@@ -67,14 +67,14 @@ class SummarizingStatsReceiver extends StatsReceiverWithCumulativeGauges {
 
     val counterLines = (counterValues map { case (k, v) => (variableName(k), v.toString) }).toSeq
     val statLines = (statValues map { case (k, xs) =>
-      val n = xs.size
+      val n = xs.length
       def idx(ptile: Double) = math.floor(ptile*n).toInt
       (variableName(k), "n=%d min=%.1f med=%.1f p90=%.1f p95=%.1f p99=%.1f p999=%.1f p9999=%.1f max=%.1f".format(
         n, xs(0), xs(n/2), xs(idx(.9D)), xs(idx(.95D)), xs(idx(.99D)), xs(idx(.999D)), xs(idx(.9999D)), xs(n-1)))
     }).toSeq
 
     lazy val tailValues = (statValues map { case (k, xs) =>
-      val n = xs.size
+      val n = xs.length
       def slice(ptile: Double) = {
         val end = math.floor(ptile*n).toInt
         val start = math.ceil(end-((1.0-ptile)*n)).toInt

diff --git a/finagle-core/src/main/scala/com/twitter/finagle/util/InetSocketAddressUtil.scala b/finagle-core/src/main/scala/com/twitter/finagle/util/InetSocketAddressUtil.scala
@@ -38,7 +38,7 @@ object InetSocketAddressUtil {
    */
   def parseHostPorts(hosts: String): Seq[HostPort] =
     hosts split Array(' ', ',') filter (_.nonEmpty) map (_.split(":")) map { hp =>
-      require(hp.size == 2, "You must specify host and port")
+      require(hp.length == 2, "You must specify host and port")
       hp match {
         case Array(host, "*") => (host, 0)
         case Array(host, portStr) => (host, portStr.toInt)

diff --git a/finagle-core/src/main/scala/com/twitter/finagle/util/LoadService.scala b/finagle-core/src/main/scala/com/twitter/finagle/util/LoadService.scala
@@ -147,10 +147,10 @@ private object ClassPath {
         val commentIdx = line.indexOf('#')
         val end = if (commentIdx != -1) commentIdx else line.length
         val str = line.substring(0, end).trim
-        if (str.isEmpty) Seq.empty else Seq(str)
+        if (str.isEmpty) Nil else Seq(str)
       }
     } catch {
-      case ex: MalformedInputException => Seq.empty /* skip malformed files (e.g. non UTF-8) */
+      case ex: MalformedInputException => Nil /* skip malformed files (e.g. non UTF-8) */
     } finally {
       source.close()
     }

diff --git a/finagle-http/src/main/scala/com/twitter/finagle/http/codec/HttpDtab.scala b/finagle-http/src/main/scala/com/twitter/finagle/http/codec/HttpDtab.scala
@@ -69,10 +69,10 @@ object HttpDtab {
     }
 
   private def validHeaderPair(aKey: String, bKey: String): Boolean =
-    aKey.size == bKey.size &&
-    aKey.substring(0, aKey.size-1) == bKey.substring(0, bKey.size-1) &&
-    aKey(aKey.size-1) == 'a' &&
-    bKey(bKey.size-1) == 'b'
+    aKey.length == bKey.length &&
+    aKey.charAt(aKey.length - 1) == 'a' &&
+    bKey.charAt(bKey.length - 1) == 'b' &&
+    aKey.substring(0, aKey.length - 1) == bKey.substring(0, bKey.length - 1)
 
   private val EmptyReturn = Return(Dtab.empty)
 
@@ -99,7 +99,7 @@ object HttpDtab {
       // TODO: now that we have a proper Dtab grammar,
       // should just embed this directly instead.
       msg.headers.set(Prefix+indexstr(i)+"-A", b64Encode(prefix.show))
-      msg.headers.set(Prefix+indexstr(i)+"-B".format(i), b64Encode(dst.show))
+      msg.headers.set(Prefix+indexstr(i)+"-B", b64Encode(dst.show))
     }
   }
 

diff --git a/finagle-http/src/main/scala/com/twitter/finagle/http/filter/Cors.scala b/finagle-http/src/main/scala/com/twitter/finagle/http/filter/Cors.scala
@@ -37,7 +37,7 @@ object Cors {
     allowsOrigin: String => Option[String],
     allowsMethods: String => Option[Seq[String]],
     allowsHeaders: Seq[String] => Option[Seq[String]],
-    exposedHeaders: Seq[String] = Seq.empty,
+    exposedHeaders: Seq[String] = Nil,
     supportsCredentials: Boolean = false,
     maxAge: Option[Duration] = None)
 

diff --git a/finagle-httpx/src/main/scala/com/twitter/finagle/httpx/codec/HttpDtab.scala b/finagle-httpx/src/main/scala/com/twitter/finagle/httpx/codec/HttpDtab.scala
@@ -69,10 +69,10 @@ object HttpDtab {
     }
 
   private def validHeaderPair(aKey: String, bKey: String): Boolean =
-    aKey.size == bKey.size &&
-    aKey.substring(0, aKey.size-1) == bKey.substring(0, bKey.size-1) &&
-    aKey(aKey.size-1) == 'a' &&
-    bKey(bKey.size-1) == 'b'
+    aKey.length == bKey.length &&
+    aKey(aKey.length - 1) == 'a' &&
+    bKey(bKey.length - 1) == 'b' &&
+    aKey.substring(0, aKey.length - 1) == bKey.substring(0, bKey.length - 1)
 
   private val EmptyReturn = Return(Dtab.empty)
 
@@ -99,7 +99,7 @@ object HttpDtab {
       // TODO: now that we have a proper Dtab grammar,
       // should just embed this directly instead.
       msg.headers.set(Prefix+indexstr(i)+"-A", b64Encode(prefix.show))
-      msg.headers.set(Prefix+indexstr(i)+"-B".format(i), b64Encode(dst.show))
+      msg.headers.set(Prefix+indexstr(i)+"-B", b64Encode(dst.show))
     }
   }
 

diff --git a/finagle-httpx/src/main/scala/com/twitter/finagle/httpx/filter/Cors.scala b/finagle-httpx/src/main/scala/com/twitter/finagle/httpx/filter/Cors.scala
@@ -36,7 +36,7 @@ object Cors {
     allowsOrigin: String => Option[String],
     allowsMethods: String => Option[Seq[String]],
     allowsHeaders: Seq[String] => Option[Seq[String]],
-    exposedHeaders: Seq[String] = Seq.empty,
+    exposedHeaders: Seq[String] = Nil,
     supportsCredentials: Boolean = false,
     maxAge: Option[Duration] = None)
 

diff --git a/...memcached/src/main/scala/com/twitter/finagle/memcached/protocol/text/client/Decoder.scala b/...memcached/src/main/scala/com/twitter/finagle/memcached/protocol/text/client/Decoder.scala
@@ -70,7 +70,7 @@ class Decoder extends AbstractDecoder with StateMachine {
   final protected[memcached] def awaitData(tokens: Seq[ChannelBuffer], bytesNeeded: Int) = {
     state match {
       case AwaitingResponse() =>
-        awaitData(Seq(), tokens, bytesNeeded)
+        awaitData(Nil, tokens, bytesNeeded)
       case AwaitingResponseOrEnd(valuesSoFar) =>
         awaitData(valuesSoFar, tokens, bytesNeeded)
     }

diff --git a/finagle-memcached/src/main/scala/com/twitter/finagle/memcached/util/ChannelBufferUtils.scala b/finagle-memcached/src/main/scala/com/twitter/finagle/memcached/util/ChannelBufferUtils.scala
@@ -42,7 +42,7 @@ private[finagle] object ChannelBufferUtils {
       split(FIND_SPACE, 1)
 
     def split(delimiter: String): Seq[ChannelBuffer] =
-      split(stringToChannelBufferIndexFinder(delimiter), delimiter.size)
+      split(stringToChannelBufferIndexFinder(delimiter), delimiter.length)
 
     def split(indexFinder: ChannelBufferIndexFinder, delimiterLength: Int): Seq[ChannelBuffer] = {
       val tokens = new ArrayBuffer[ChannelBuffer]
@@ -101,14 +101,13 @@ private[finagle] object ChannelBufferUtils {
   implicit def stringToChannelBufferIndexFinder(string: String): ChannelBufferIndexFinder =
     new ChannelBufferIndexFinder {
       def find(buffer: ChannelBuffer, guessedIndex: Int): Boolean = {
-        val array = string.toArray
-        var i: Int = 0
-        while (i < string.size) {
-          if (buffer.getByte(guessedIndex + i) != array(i).toByte)
+        var i = 0
+        while (i < string.length) {
+          if (buffer.getByte(guessedIndex + i) != string.charAt(i).toByte)
             return false
           i += 1
         }
-        return true
+        true
       }
     }
 }
diff --git a/...mcachedx/src/main/scala/com/twitter/finagle/memcachedx/protocol/text/client/Decoder.scala b/...mcachedx/src/main/scala/com/twitter/finagle/memcachedx/protocol/text/client/Decoder.scala
@@ -72,7 +72,7 @@ class Decoder extends AbstractDecoder with StateMachine {
   final protected[memcachedx] def awaitData(tokens: Seq[ChannelBuffer], bytesNeeded: Int) = {
     state match {
       case AwaitingResponse() =>
-        awaitData(Seq(), tokens, bytesNeeded)
+        awaitData(Nil, tokens, bytesNeeded)
       case AwaitingResponseOrEnd(valuesSoFar) =>
         awaitData(valuesSoFar, tokens, bytesNeeded)
     }

diff --git a/...le-memcachedx/src/main/scala/com/twitter/finagle/memcachedx/util/ChannelBufferUtils.scala b/...le-memcachedx/src/main/scala/com/twitter/finagle/memcachedx/util/ChannelBufferUtils.scala
@@ -42,7 +42,7 @@ private[finagle] object ChannelBufferUtils {
       split(FIND_SPACE, 1)
 
     def split(delimiter: String): Seq[ChannelBuffer] =
-      split(stringToChannelBufferIndexFinder(delimiter), delimiter.size)
+      split(stringToChannelBufferIndexFinder(delimiter), delimiter.length)
 
     def split(indexFinder: ChannelBufferIndexFinder, delimiterLength: Int): Seq[ChannelBuffer] = {
       val tokens = new ArrayBuffer[ChannelBuffer]
@@ -101,14 +101,13 @@ private[finagle] object ChannelBufferUtils {
   implicit def stringToChannelBufferIndexFinder(string: String): ChannelBufferIndexFinder =
     new ChannelBufferIndexFinder {
       def find(buffer: ChannelBuffer, guessedIndex: Int): Boolean = {
-        val array = string.toArray
-        var i: Int = 0
-        while (i < string.size) {
-          if (buffer.getByte(guessedIndex + i) != array(i).toByte)
+        var i = 0
+        while (i < string.length) {
+          if (buffer.getByte(guessedIndex + i) != string.charAt(i).toByte)
             return false
           i += 1
         }
-        return true
+        true
       }
     }
 }
diff --git a/finagle-mux/src/main/scala/com/twitter/finagle/mux/Proto.scala b/finagle-mux/src/main/scala/com/twitter/finagle/mux/Proto.scala
@@ -193,7 +193,7 @@ private[finagle] object Message {
       }
 
       val dstbytes = if (dst.isEmpty) noBytes else dst.show.getBytes(Charsets.Utf8)
-      n += 2 + dstbytes.size
+      n += 2 + dstbytes.length
       n += 2
 
       val dtabbytes = new Array[(Array[Byte], Array[Byte])](dtab.size)
@@ -204,7 +204,7 @@ private[finagle] object Message {
         val srcbytes = src.show.getBytes(Charsets.Utf8)
         val treebytes = tree.show.getBytes(Charsets.Utf8)
 
-        n += srcbytes.size + 2 + treebytes.size + 2
+        n += srcbytes.length + 2 + treebytes.length + 2
 
         dtabbytes(dtabidx) = (srcbytes, treebytes)
         dtabidx += 1
@@ -225,16 +225,16 @@ private[finagle] object Message {
         seq = seq.tail
       }
 
-      hd.writeShort(dstbytes.size)
+      hd.writeShort(dstbytes.length)
       hd.writeBytes(dstbytes)
 
       hd.writeShort(dtab.size)
       dtabidx = 0
-      while (dtabidx != dtabbytes.size) {
+      while (dtabidx != dtabbytes.length) {
         val (srcbytes, treebytes) = dtabbytes(dtabidx)
-        hd.writeShort(srcbytes.size)
+        hd.writeShort(srcbytes.length)
         hd.writeBytes(srcbytes)
-        hd.writeShort(treebytes.size)
+        hd.writeShort(treebytes.length)
         hd.writeBytes(treebytes)
         dtabidx += 1
       }
@@ -439,8 +439,10 @@ private[finagle] object Message {
       nkeys -= 1
     }
 
-    val id = trace3 map { case (spanId, parentId, traceId) =>
-      TraceId(Some(traceId), Some(parentId), spanId, None, Flags(traceFlags))
+    val id = trace3 match {
+      case Some((spanId, parentId, traceId)) =>
+        Some(TraceId(Some(traceId), Some(parentId), spanId, None, Flags(traceFlags)))
+      case None => None
     }
 
     Treq(tag, id, buf.slice())
@@ -449,7 +451,7 @@ private[finagle] object Message {
   private def decodeContexts(buf: ChannelBuffer): Seq[(ChannelBuffer, ChannelBuffer)] = {
     val n = buf.readUnsignedShort()
     if (n == 0)
-      return Seq.empty
+      return Nil
 
     val contexts = new Array[(ChannelBuffer, ChannelBuffer)](n)
     var i = 0