Checkpoint work on MTP and PTP investigation.

This change includes work in progress on a C++ library for both host and device
MTP and PTP support.
Currently the makefile builds two test programs:

mtptest - a command line test program that implements a small subset of device side MTP.
Requires a kernel driver that has not been checked in yet.

ptptest - a host tool to test USB host support for detecting and communicating with
digital cameras over PTP.  Runs on Linux host.

Later this will be reformulated as a native library that will be used in the media process.

Change-Id: I81aab279975b600b59d99013ab97f9adf0b58da7
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 133 insertions, 0 deletions

diff --git a/media/mtp/MtpStringBuffer.cpp b/media/mtp/MtpStringBuffer.cpp
new file mode 100644
index 0000000..6b55c44
--- /dev/null
+++ b/media/mtp/MtpStringBuffer.cpp
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <string.h>
+
+#include "MtpDataPacket.h"
+#include "MtpStringBuffer.h"
+
+
+MtpStringBuffer::MtpStringBuffer()
+    :   mCharCount(0),
+        mByteCount(1)
+{
+    mBuffer[0] = 0;
+}
+
+MtpStringBuffer::MtpStringBuffer(const char* src)
+    :   mCharCount(0),
+        mByteCount(1)
+{
+    set(src);
+}
+
+MtpStringBuffer::MtpStringBuffer(const MtpStringBuffer& src)
+    :   mCharCount(src.mCharCount),
+        mByteCount(src.mByteCount)
+{
+    memcpy(mBuffer, src.mBuffer, mByteCount);
+}
+
+
+MtpStringBuffer::~MtpStringBuffer() {
+}
+
+void MtpStringBuffer::set(const char* src) {
+    int length = strlen(src);
+    if (length >= sizeof(mBuffer))
+        length = sizeof(mBuffer) - 1;
+    memcpy(mBuffer, src, length);
+
+    // count the characters
+    int count = 0;
+    char ch;
+    while ((ch = *src++) != 0) {
+        if ((ch & 0x80) == 0) {
+            // single byte character
+        } else if ((ch & 0xE0) == 0xC0) {
+            // two byte character
+            if (! *src++) {
+                // last character was truncated, so ignore last byte
+                length--;
+                break;
+            }
+        } else if ((ch & 0xF0) == 0xE0) {
+            // 3 byte char
+            if (! *src++) {
+                // last character was truncated, so ignore last byte
+                length--;
+                break;
+            }
+            if (! *src++) {
+                // last character was truncated, so ignore last two bytes
+                length -= 2;
+                break;
+            }
+        }
+        count++;
+    }
+
+    mByteCount = length + 1;
+    mBuffer[length] = 0;
+    mCharCount = count;
+}
+
+void MtpStringBuffer::readFromPacket(MtpDataPacket* packet) {
+    int count = packet->getUInt8();
+    uint8_t* dest = mBuffer;
+    for (int i = 0; i < count; i++) {
+        uint16_t ch = packet->getUInt16();
+        if (ch >= 0x0800) {
+            *dest++ = (uint8_t)(0xE0 | (ch >> 12));
+            *dest++ = (uint8_t)(0x80 | ((ch >> 6) & 0x3F));
+            *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
+        } else if (ch >= 0x80) {
+            *dest++ = (uint8_t)(0xC0 | (ch >> 6));
+            *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
+        } else {
+            *dest++ = ch;
+        }
+    }
+    *dest++ = 0;
+    mCharCount = count;
+    mByteCount = dest - mBuffer;
+}
+
+void MtpStringBuffer::writeToPacket(MtpDataPacket* packet) const {
+    int count = mCharCount;
+    const uint8_t* src = mBuffer;
+    packet->putUInt8(count);
+
+    // expand utf8 to 16 bit chars
+    for (int i = 0; i < count; i++) {
+        uint16_t ch;
+        uint16_t ch1 = *src++;
+        if ((ch1 & 0x80) == 0) {
+            // single byte character
+            ch = ch1;
+        } else if ((ch1 & 0xE0) == 0xC0) {
+            // two byte character
+            uint16_t ch2 = *src++;
+            ch = ((ch1 & 0x1F) << 6) | (ch2 & 0x3F);
+        } else {
+            // three byte character
+            uint16_t ch2 = *src++;
+            uint16_t ch3 = *src++;
+            ch = ((ch1 & 0x0F) << 12) | ((ch2 & 0x3F) << 6) | (ch3 & 0x3F);
+        }
+        packet->putUInt16(ch);
+    }
+}