Initial Contribution
diff --git a/simulator/app/MessageStream.cpp b/simulator/app/MessageStream.cpp
new file mode 100644
index 0000000..2397c63
--- /dev/null
+++ b/simulator/app/MessageStream.cpp
@@ -0,0 +1,402 @@
+//
+// Copyright 2005 The Android Open Source Project
+//
+// Message stream abstraction.
+//
+#include "MessageStream.h"
+#include "LogBundle.h"
+
+#include "utils/Log.h"
+
+#include <string.h>
+#include <assert.h>
+
+using namespace android;
+
+/*
+ * ===========================================================================
+ *      Message
+ * ===========================================================================
+ */
+
+/*
+ * Send a blob of raw data.
+ */
+void Message::setRaw(const unsigned char* data, int len, Cleanup cleanup)
+{
+    reset();
+
+    mData = const_cast<unsigned char*>(data);
+    mLength = len;
+    mCleanup = cleanup;
+    mType = kTypeRaw;
+}
+
+/*
+ * Send a "name=value" config pair.
+ */
+void Message::setConfig(const char* name, const char* value)
+{
+    reset();
+
+    assert(name != NULL && value != NULL);
+
+    int nlen = strlen(name) +1;
+    int vlen = strlen(value) +1;
+    mData = new unsigned char[nlen+vlen];
+    mCleanup = kCleanupDelete;
+    mLength = nlen + vlen;
+    mType = kTypeConfig;
+
+    memcpy(mData, name, nlen);
+    memcpy(mData + nlen, value, vlen);
+}
+
+/*
+ * Try to return the contents of the message as if it were a name/value pair.
+ */
+bool Message::getConfig(const char** pName, const char** pValue)
+{
+    if (mLength < 2)
+        return false;
+    assert(mData != NULL);
+
+    *pName = (const char*) mData;
+    *pValue = (const char*) (mData + strlen((char*)mData) +1);
+    return true;
+}
+
+/*
+ * Send a command/arg pair.
+ */
+void Message::setCommand(int cmd, int arg)
+{
+    reset();
+
+    mData = new unsigned char[sizeof(int) * 2];
+    mCleanup = kCleanupDelete;
+    mLength = sizeof(int) * 2;
+    mType = kTypeCommand;
+
+    int* pInt = (int*) mData;
+    pInt[0] = cmd;
+    pInt[1] = arg;
+}
+
+/*
+ * Send a command with 3 args instead of just one.
+ */
+void Message::setCommandExt(int cmd, int arg0, int arg1, int arg2)
+{
+    reset();
+
+    mData = new unsigned char[sizeof(int) * 4];
+    mCleanup = kCleanupDelete;
+    mLength = sizeof(int) * 4;
+    mType = kTypeCommandExt;
+
+    int* pInt = (int*) mData;
+    pInt[0] = cmd;
+    pInt[1] = arg0;
+    pInt[2] = arg1;
+    pInt[3] = arg2;
+}
+
+/*
+ * Try to return the contents of the message as if it were a "command".
+ */
+bool Message::getCommand(int* pCmd, int* pArg)
+{
+    if (mLength != sizeof(int) * 2) {
+        LOG(LOG_WARN, "", "type is %d, len is %d\n", mType, mLength);
+        return false;
+    }
+    assert(mData != NULL);
+
+    const int* pInt = (const int*) mData;
+    *pCmd = pInt[0];
+    *pArg = pInt[1];
+
+    return true;
+}
+
+/*
+ * Serialize a log message.
+ *
+ * DO NOT call LOG() from here.
+ */
+void Message::setLogBundle(const android_LogBundle* pBundle)
+{
+    reset();
+
+    /* get string lengths; we add one here to include the '\0' */
+    int tagLen, msgLen;
+    tagLen = strlen(pBundle->tag) + 1;
+    size_t i;
+    msgLen = 0;
+    for (i=0; i<pBundle->msgCount; i++) msgLen += pBundle->msgVec[i].iov_len;
+    msgLen += 1;
+
+    /* set up the structure */
+    mCleanup = kCleanupDelete;
+    mLength =   sizeof(pBundle->when) +
+                sizeof(pBundle->priority) +
+                sizeof(pBundle->pid) +
+                tagLen +
+                msgLen;
+    mData = new unsigned char[mLength];
+    mType = kTypeLogBundle;
+
+    unsigned char* pCur = mData;
+
+    /* copy the stuff over */
+    *((time_t*)pCur) = pBundle->when;
+    pCur += sizeof(pBundle->when);
+    *((android_LogPriority*)pCur) = pBundle->priority;
+    pCur += sizeof(pBundle->priority);
+    *((pid_t*)pCur) = pBundle->pid;
+    pCur += sizeof(pBundle->pid);
+    memcpy(pCur, pBundle->tag, tagLen);
+    pCur += tagLen;
+    for (i=0; i<pBundle->msgCount; i++) {
+        memcpy(pCur, pBundle->msgVec[i].iov_base, pBundle->msgVec[i].iov_len);
+        pCur += pBundle->msgVec[i].iov_len;
+    }
+    *pCur++ = 0;
+
+    assert(pCur - mData == mLength);
+}
+
+/*
+ * Extract the components of a log bundle.
+ *
+ * We're just returning points inside the message buffer, so the caller
+ * will need to copy them out before the next reset().
+ */
+bool Message::getLogBundle(android_LogBundle* pBundle)
+{
+    if (mLength < (int)(sizeof(time_t) + sizeof(int)*2 + 4)) {
+        LOG(LOG_WARN, "", "type is %d, len is %d, too small\n",
+            mType, mLength);
+        return false;
+    }
+    assert(mData != NULL);
+
+    unsigned char* pCur = mData;
+
+    pBundle->when = *((time_t*) pCur);
+    pCur += sizeof(pBundle->when);
+    pBundle->priority = *((android_LogPriority*) pCur);
+    pCur += sizeof(pBundle->priority);
+    pBundle->pid = *((pid_t*) pCur);
+    pCur += sizeof(pBundle->pid);
+    pBundle->tag = (const char*) pCur;
+    pCur += strlen((const char*) pCur) +1;
+    mVec.iov_base = (char*) pCur;
+    mVec.iov_len = strlen((const char*) pCur);
+    pBundle->msgVec = &mVec;
+    pBundle->msgCount = 1;
+    pCur += mVec.iov_len +1;
+
+    if (pCur - mData != mLength) {
+        LOG(LOG_WARN, "", "log bundle rcvd %d, used %d\n", mLength,
+            (int) (pCur - mData));
+        return false;
+    }
+
+    return true;
+}
+
+/*
+ * Read the next event from the pipe.
+ *
+ * This is not expected to work well when multiple threads are reading.
+ */
+bool Message::read(Pipe* pPipe, bool wait)
+{
+    if (pPipe == NULL)
+        return false;
+    assert(pPipe->isCreated());
+
+    if (!wait) {
+        if (!pPipe->readReady())
+            return false;
+    }
+
+    reset();
+
+    unsigned char header[4];
+    if (pPipe->read(header, 4) != 4)
+        return false;
+
+    mType = (MessageType) header[2];
+    mLength = header[0] | header[1] << 8;
+    mLength -= 2;   // we already read two of them in the header
+
+    if (mLength > 0) {
+        int actual;
+
+        mData = new unsigned char[mLength];
+        if (mData == NULL) {
+            LOG(LOG_ERROR, "", "alloc failed\n");
+            return false;
+        }
+        mCleanup = kCleanupDelete;
+
+        actual = pPipe->read(mData, mLength);
+        if (actual != mLength) {
+            LOG(LOG_WARN, "", "failed reading message body (%d of %d bytes)\n",
+                actual, mLength);
+            return false;
+        }
+    }
+
+    return true;
+}
+
+/*
+ * Write this event to a pipe.
+ *
+ * It would be easiest to write the header and message body with two
+ * separate calls, but that will occasionally fail on multithreaded
+ * systems when the writes are interleaved.  We have to allocate a
+ * temporary buffer, copy the data, and write it all at once.  This
+ * would be easier with writev(), but we can't rely on having that.
+ *
+ * DO NOT call LOG() from here, as we could be in the process of sending
+ * a log message.
+ */
+bool Message::write(Pipe* pPipe) const
+{
+    char tmpBuf[128];
+    char* writeBuf = tmpBuf;
+    bool result = false;
+    int kHeaderLen = 4;
+
+    if (pPipe == NULL)
+        return false;
+    assert(pPipe->isCreated());
+
+    if (mData == NULL || mLength < 0)
+        return false;
+
+    /* if it doesn't fit in stack buffer, allocate space */
+    if (mLength + kHeaderLen > (int) sizeof(tmpBuf)) {
+        writeBuf = new char[mLength + kHeaderLen];
+        if (writeBuf == NULL)
+            goto bail;
+    }
+
+    /*
+     * The current value of "mLength" does not include the 4-byte header.
+     * Two of the 4 header bytes are included in the length we output
+     * (the type byte and the pad byte), so we adjust mLength.
+     */
+    writeBuf[0] = (unsigned char) (mLength + kHeaderLen -2);
+    writeBuf[1] = (unsigned char) ((mLength + kHeaderLen -2) >> 8);
+    writeBuf[2] = (unsigned char) mType;
+    writeBuf[3] = 0;
+    if (mLength > 0)
+        memcpy(writeBuf + kHeaderLen, mData, mLength);
+
+    int actual;
+
+    actual = pPipe->write(writeBuf, mLength + kHeaderLen);
+    if (actual != mLength + kHeaderLen) {
+        fprintf(stderr,
+            "Message::write failed writing message body (%d of %d bytes)\n",
+            actual, mLength + kHeaderLen);
+        goto bail;
+    }
+
+    result = true;
+
+bail:
+    if (writeBuf != tmpBuf)
+        delete[] writeBuf;
+    return result;
+}
+
+
+/*
+ * ===========================================================================
+ *      MessageStream
+ * ===========================================================================
+ */
+
+/*
+ * Get ready to go.
+ */
+bool MessageStream::init(Pipe* readPipe, Pipe* writePipe, bool initiateHello)
+{
+    assert(mReadPipe == NULL && mWritePipe == NULL);    // only once
+
+    /*
+     * Swap "hello" messages.
+     *
+     * In a more robust implementation, this would include version numbers
+     * and capability flags.
+     */
+    if (initiateHello) {
+        long data = kHelloMsg;
+        Message msg;
+
+        /* send hello */
+        msg.setRaw((unsigned char*) &data, sizeof(data),
+            Message::kCleanupNoDelete);
+        if (!msg.write(writePipe)) {
+            LOG(LOG_WARN, "", "hello write failed in stream init\n");
+            return false;
+        }
+
+        LOG(LOG_DEBUG, "", "waiting for peer to ack my hello\n");
+
+        /* wait for the ack */
+        if (!msg.read(readPipe, true)) {
+            LOG(LOG_WARN, "", "hello ack read failed in stream init\n");
+            return false;
+        }
+
+        const long* pAck;
+        pAck = (const long*) msg.getData();
+        if (pAck == NULL || *pAck != kHelloAckMsg) {
+            LOG(LOG_WARN, "", "hello ack was bad\n");
+            return false;
+        }
+    } else {
+        long data = kHelloAckMsg;
+        Message msg;
+
+        LOG(LOG_DEBUG, "", "waiting for hello from peer\n");
+
+        /* wait for the hello */
+        if (!msg.read(readPipe, true)) {
+            LOG(LOG_WARN, "", "hello read failed in stream init\n");
+            return false;
+        }
+
+        const long* pAck;
+        pAck = (const long*) msg.getData();
+        if (pAck == NULL || *pAck != kHelloMsg) {
+            LOG(LOG_WARN, "", "hello was bad\n");
+            return false;
+        }
+
+        /* send hello ack */
+        msg.setRaw((unsigned char*) &data, sizeof(data),
+            Message::kCleanupNoDelete);
+        if (!msg.write(writePipe)) {
+            LOG(LOG_WARN, "", "hello ack write failed in stream init\n");
+            return false;
+        }
+    }
+
+    /* success, set up our local stuff */
+    mReadPipe = readPipe;
+    mWritePipe = writePipe;
+
+    //LOG(LOG_DEBUG, "", "init success\n");
+
+    return true;
+}
+