add a spec/demo of a simple http request parser.

src/test/scala/net/lag/naggati/HttpRequestSpec.scala

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2009 Robey Pointer <robeypointer@lag.net>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.lag.naggati
+
+import net.lag.naggati.Steps._
+import org.apache.mina.core.buffer.IoBuffer
+import org.apache.mina.core.filterchain.IoFilter
+import org.apache.mina.core.session.{DummySession, IoSession}
+import org.apache.mina.filter.codec.ProtocolDecoderOutput
+import org.specs._
+import scala.collection.mutable
+
+
+case class RequestLine(method: String, resource: String, version: String)
+case class HeaderLine(name: String, value: String)
+case class HttpRequest(request: RequestLine, headers: List[HeaderLine], body: Array[Byte])
+
+object HttpRequestDecoder {
+  def readRequest = {
+    readLine(true, "UTF-8") { line =>
+      line.split(' ').toList match {
+        case method :: resource :: version :: Nil =>
+          state("request") = RequestLine(method, resource, version)
+          state("headers") = new mutable.ListBuffer[HeaderLine]
+          readHeader
+        case _ => throw new ProtocolError("Malformed request line: " + line)
+      }
+    }
+  }
+
+  val readHeader: Step = readLine(true, "UTF-8") { line =>
+    val headers: mutable.ListBuffer[HeaderLine] = state("headers")
+    if (line == "") {
+      // end of headers
+      val contentLength = headers find { _.name == "content-length" } map { _.value.toInt } getOrElse 0
+      readByteBuffer(contentLength) { data =>
+        state.out.write(new HttpRequest(state("request"), headers.toList, data))
+        End
+      }
+    } else if (line.length > 0 && (line.first == ' ' || line.first == '\t')) {
+      // continuation line
+      if (headers.size == 0) {
+        throw new ProtocolError("Malformed header line: " + line)
+      }
+      val newHeaderLine = HeaderLine(headers.last.name, headers.last.value + " " + line.trim)
+      headers.trimEnd(1)
+      headers += newHeaderLine
+      readHeader
+    } else {
+      line.split(':').toList match {
+        case name :: value :: Nil => headers += HeaderLine(name.trim.toLowerCase, value.trim)
+        case _ => throw new ProtocolError("Malformed header line: " + line)
+      }
+      readHeader
+    }
+  }
+}
+
+
+object HttpRequestSpec extends Specification {
+
+  private var fakeSession: IoSession = null
+  private var fakeDecoderOutput: ProtocolDecoderOutput = null
+  private var written = new mutable.ListBuffer[HttpRequest]
+
+  def quickDecode(decoder: Decoder, s: String): Unit = {
+    decoder.decode(fakeSession, IoBuffer.wrap(s.getBytes), fakeDecoderOutput)
+  }
+
+  val TEST1 = """POST /query.cgi HTTP/1.1
+Host: www.example.com
+Content-Length: 6
+X-Special-Request: cheese
+ and ham
+
+hello!"""
+
+  "HttpRequestDecoder" should {
+    doBefore {
+      written.clear()
+      fakeSession = new DummySession
+      fakeDecoderOutput = new ProtocolDecoderOutput {
+        override def flush(nextFilter: IoFilter.NextFilter, s: IoSession) = {}
+        override def write(obj: AnyRef) = written += obj.asInstanceOf[HttpRequest]
+      }
+    }
+
+    "parse a simple http request" in {
+      3 mustEqual 3
+      val decoder = new Decoder(HttpRequestDecoder.readRequest)
+      quickDecode(decoder, TEST1)
+
+      written.size mustEqual 1
+      written(0).request mustEqual RequestLine("POST", "/query.cgi", "HTTP/1.1")
+      written(0).headers.size mustEqual 3
+      written(0).headers(0) mustEqual HeaderLine("host", "www.example.com")
+      written(0).headers(1) mustEqual HeaderLine("content-length", "6")
+      written(0).headers(2) mustEqual HeaderLine("x-special-request", "cheese and ham")
+      new String(written(0).body) mustEqual "hello!"
+    }
+  }
+}