media/libstagefright/foundation/AMessage.cpp

/*
 * 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 "AMessage.h"

#include <ctype.h>

#include "AAtomizer.h"
#include "ABuffer.h"
#include "ADebug.h"
#include "ALooperRoster.h"
#include "AString.h"

#include <binder/Parcel.h>
#include <media/stagefright/foundation/hexdump.h>

namespace android {

extern ALooperRoster gLooperRoster;

AMessage::AMessage(uint32_t what, ALooper::handler_id target)
    : mWhat(what),
      mTarget(target),
      mNumItems(0) {
}

AMessage::~AMessage() {
    clear();
}

void AMessage::setWhat(uint32_t what) {
    mWhat = what;
}

uint32_t AMessage::what() const {
    return mWhat;
}

void AMessage::setTarget(ALooper::handler_id handlerID) {
    mTarget = handlerID;
}

ALooper::handler_id AMessage::target() const {
    return mTarget;
}

void AMessage::clear() {
    for (size_t i = 0; i < mNumItems; ++i) {
        Item *item = &mItems[i];
        freeItem(item);
    }
    mNumItems = 0;
}

void AMessage::freeItem(Item *item) {
    switch (item->mType) {
        case kTypeString:
        {
            delete item->u.stringValue;
            break;
        }

        case kTypeObject:
        case kTypeMessage:
        case kTypeBuffer:
        {
            if (item->u.refValue != NULL) {
                item->u.refValue->decStrong(this);
            }
            break;
        }

        default:
            break;
    }
}

AMessage::Item *AMessage::allocateItem(const char *name) {
    name = AAtomizer::Atomize(name);

    size_t i = 0;
    while (i < mNumItems && mItems[i].mName != name) {
        ++i;
    }

    Item *item;

    if (i < mNumItems) {
        item = &mItems[i];
        freeItem(item);
    } else {
        CHECK(mNumItems < kMaxNumItems);
        i = mNumItems++;
        item = &mItems[i];

        item->mName = name;
    }

    return item;
}

const AMessage::Item *AMessage::findItem(
        const char *name, Type type) const {
    name = AAtomizer::Atomize(name);

    for (size_t i = 0; i < mNumItems; ++i) {
        const Item *item = &mItems[i];

        if (item->mName == name) {
            return item->mType == type ? item : NULL;
        }
    }

    return NULL;
}

#define BASIC_TYPE(NAME,FIELDNAME,TYPENAME)                             \
void AMessage::set##NAME(const char *name, TYPENAME value) {            \
    Item *item = allocateItem(name);                                    \
                                                                        \
    item->mType = kType##NAME;                                          \
    item->u.FIELDNAME = value;                                          \
}                                                                       \
                                                                        \
bool AMessage::find##NAME(const char *name, TYPENAME *value) const {    \
    const Item *item = findItem(name, kType##NAME);                     \
    if (item) {                                                         \
        *value = item->u.FIELDNAME;                                     \
        return true;                                                    \
    }                                                                   \
    return false;                                                       \
}

BASIC_TYPE(Int32,int32Value,int32_t)
BASIC_TYPE(Int64,int64Value,int64_t)
BASIC_TYPE(Size,sizeValue,size_t)
BASIC_TYPE(Float,floatValue,float)
BASIC_TYPE(Double,doubleValue,double)
BASIC_TYPE(Pointer,ptrValue,void *)

#undef BASIC_TYPE

void AMessage::setString(
        const char *name, const char *s, ssize_t len) {
    Item *item = allocateItem(name);
    item->mType = kTypeString;
    item->u.stringValue = new AString(s, len < 0 ? strlen(s) : len);
}

void AMessage::setObjectInternal(
        const char *name, const sp<RefBase> &obj, Type type) {
    Item *item = allocateItem(name);
    item->mType = type;

    if (obj != NULL) { obj->incStrong(this); }
    item->u.refValue = obj.get();
}

void AMessage::setObject(const char *name, const sp<RefBase> &obj) {
    setObjectInternal(name, obj, kTypeObject);
}

void AMessage::setBuffer(const char *name, const sp<ABuffer> &buffer) {
    setObjectInternal(name, sp<RefBase>(buffer), kTypeBuffer);
}

void AMessage::setMessage(const char *name, const sp<AMessage> &obj) {
    Item *item = allocateItem(name);
    item->mType = kTypeMessage;

    if (obj != NULL) { obj->incStrong(this); }
    item->u.refValue = obj.get();
}

void AMessage::setRect(
        const char *name,
        int32_t left, int32_t top, int32_t right, int32_t bottom) {
    Item *item = allocateItem(name);
    item->mType = kTypeRect;

    item->u.rectValue.mLeft = left;
    item->u.rectValue.mTop = top;
    item->u.rectValue.mRight = right;
    item->u.rectValue.mBottom = bottom;
}

bool AMessage::findString(const char *name, AString *value) const {
    const Item *item = findItem(name, kTypeString);
    if (item) {
        *value = *item->u.stringValue;
        return true;
    }
    return false;
}

bool AMessage::findObject(const char *name, sp<RefBase> *obj) const {
    const Item *item = findItem(name, kTypeObject);
    if (item) {
        *obj = item->u.refValue;
        return true;
    }
    return false;
}

bool AMessage::findBuffer(const char *name, sp<ABuffer> *buf) const {
    const Item *item = findItem(name, kTypeBuffer);
    if (item) {
        *buf = (ABuffer *)(item->u.refValue);
        return true;
    }
    return false;
}

bool AMessage::findMessage(const char *name, sp<AMessage> *obj) const {
    const Item *item = findItem(name, kTypeMessage);
    if (item) {
        *obj = static_cast<AMessage *>(item->u.refValue);
        return true;
    }
    return false;
}

bool AMessage::findRect(
        const char *name,
        int32_t *left, int32_t *top, int32_t *right, int32_t *bottom) const {
    const Item *item = findItem(name, kTypeRect);
    if (item == NULL) {
        return false;
    }

    *left = item->u.rectValue.mLeft;
    *top = item->u.rectValue.mTop;
    *right = item->u.rectValue.mRight;
    *bottom = item->u.rectValue.mBottom;

    return true;
}

void AMessage::post(int64_t delayUs) {
    gLooperRoster.postMessage(this, delayUs);
}

status_t AMessage::postAndAwaitResponse(sp<AMessage> *response) {
    return gLooperRoster.postAndAwaitResponse(this, response);
}

void AMessage::postReply(uint32_t replyID) {
    gLooperRoster.postReply(replyID, this);
}

bool AMessage::senderAwaitsResponse(uint32_t *replyID) const {
    int32_t tmp;
    bool found = findInt32("replyID", &tmp);

    if (!found) {
        return false;
    }

    *replyID = static_cast<uint32_t>(tmp);

    return true;
}

sp<AMessage> AMessage::dup() const {
    sp<AMessage> msg = new AMessage(mWhat, mTarget);
    msg->mNumItems = mNumItems;

    for (size_t i = 0; i < mNumItems; ++i) {
        const Item *from = &mItems[i];
        Item *to = &msg->mItems[i];

        to->mName = from->mName;
        to->mType = from->mType;

        switch (from->mType) {
            case kTypeString:
            {
                to->u.stringValue =
                    new AString(*from->u.stringValue);
                break;
            }

            case kTypeObject:
            case kTypeBuffer:
            {
                to->u.refValue = from->u.refValue;
                to->u.refValue->incStrong(msg.get());
                break;
            }

            case kTypeMessage:
            {
                sp<AMessage> copy =
                    static_cast<AMessage *>(from->u.refValue)->dup();

                to->u.refValue = copy.get();
                to->u.refValue->incStrong(msg.get());
                break;
            }

            default:
            {
                to->u = from->u;
                break;
            }
        }
    }

    return msg;
}

static void appendIndent(AString *s, int32_t indent) {
    static const char kWhitespace[] =
        "                                        "
        "                                        ";

    CHECK_LT((size_t)indent, sizeof(kWhitespace));

    s->append(kWhitespace, indent);
}

static bool isFourcc(uint32_t what) {
    return isprint(what & 0xff)
        && isprint((what >> 8) & 0xff)
        && isprint((what >> 16) & 0xff)
        && isprint((what >> 24) & 0xff);
}

AString AMessage::debugString(int32_t indent) const {
    AString s = "AMessage(what = ";

    AString tmp;
    if (isFourcc(mWhat)) {
        tmp = StringPrintf(
                "'%c%c%c%c'",
                (char)(mWhat >> 24),
                (char)((mWhat >> 16) & 0xff),
                (char)((mWhat >> 8) & 0xff),
                (char)(mWhat & 0xff));
    } else {
        tmp = StringPrintf("0x%08x", mWhat);
    }
    s.append(tmp);

    if (mTarget != 0) {
        tmp = StringPrintf(", target = %d", mTarget);
        s.append(tmp);
    }
    s.append(") = {\n");

    for (size_t i = 0; i < mNumItems; ++i) {
        const Item &item = mItems[i];

        switch (item.mType) {
            case kTypeInt32:
                tmp = StringPrintf(
                        "int32_t %s = %d", item.mName, item.u.int32Value);
                break;
            case kTypeInt64:
                tmp = StringPrintf(
                        "int64_t %s = %lld", item.mName, item.u.int64Value);
                break;
            case kTypeSize:
                tmp = StringPrintf(
                        "size_t %s = %d", item.mName, item.u.sizeValue);
                break;
            case kTypeFloat:
                tmp = StringPrintf(
                        "float %s = %f", item.mName, item.u.floatValue);
                break;
            case kTypeDouble:
                tmp = StringPrintf(
                        "double %s = %f", item.mName, item.u.doubleValue);
                break;
            case kTypePointer:
                tmp = StringPrintf(
                        "void *%s = %p", item.mName, item.u.ptrValue);
                break;
            case kTypeString:
                tmp = StringPrintf(
                        "string %s = \"%s\"",
                        item.mName,
                        item.u.stringValue->c_str());
                break;
            case kTypeObject:
                tmp = StringPrintf(
                        "RefBase *%s = %p", item.mName, item.u.refValue);
                break;
            case kTypeBuffer:
            {
                sp<ABuffer> buffer = static_cast<ABuffer *>(item.u.refValue);

                if (buffer != NULL && buffer->size() <= 64) {
                    tmp = StringPrintf("Buffer %s = {\n", item.mName);
                    hexdump(buffer->data(), buffer->size(), indent + 4, &tmp);
                    appendIndent(&tmp, indent + 2);
                    tmp.append("}");
                } else {
                    tmp = StringPrintf(
                            "Buffer *%s = %p", item.mName, buffer.get());
                }
                break;
            }
            case kTypeMessage:
                tmp = StringPrintf(
                        "AMessage %s = %s",
                        item.mName,
                        static_cast<AMessage *>(
                            item.u.refValue)->debugString(
                                indent + strlen(item.mName) + 14).c_str());
                break;
            case kTypeRect:
                tmp = StringPrintf(
                        "Rect %s(%d, %d, %d, %d)",
                        item.mName,
                        item.u.rectValue.mLeft,
                        item.u.rectValue.mTop,
                        item.u.rectValue.mRight,
                        item.u.rectValue.mBottom);
                break;
            default:
                TRESPASS();
        }

        appendIndent(&s, indent);
        s.append("  ");
        s.append(tmp);
        s.append("\n");
    }

    appendIndent(&s, indent);
    s.append("}");

    return s;
}

// static
sp<AMessage> AMessage::FromParcel(const Parcel &parcel) {
    int32_t what = parcel.readInt32();
    sp<AMessage> msg = new AMessage(what);

    msg->mNumItems = static_cast<size_t>(parcel.readInt32());
    if (msg->mNumItems > kMaxNumItems) {
        ALOGE("Too large number of items clipped.");
        msg->mNumItems = kMaxNumItems;
    }

    for (size_t i = 0; i < msg->mNumItems; ++i) {
        Item *item = &msg->mItems[i];

        const char *name = parcel.readCString();
        if (name == NULL) {
            ALOGE("Failed reading name for an item. Parsing aborted.");
            msg->mNumItems = i;
            break;
        }

        item->mName = AAtomizer::Atomize(name);
        item->mType = static_cast<Type>(parcel.readInt32());
        switch (item->mType) {
            case kTypeInt32:
            {
                item->u.int32Value = parcel.readInt32();
                break;
            }

            case kTypeInt64:
            {
                item->u.int64Value = parcel.readInt64();
                break;
            }

            case kTypeSize:
            {
                item->u.sizeValue = static_cast<size_t>(parcel.readInt32());
                break;
            }

            case kTypeFloat:
            {
                item->u.floatValue = parcel.readFloat();
                break;
            }

            case kTypeDouble:
            {
                item->u.doubleValue = parcel.readDouble();
                break;
            }

            case kTypeString:
            {
                const char *stringValue = parcel.readCString();
                if (stringValue == NULL) {
                    ALOGE("Failed reading string value from a parcel. "
                        "Parsing aborted.");
                    msg->mNumItems = i;
                    continue;
                    // The loop will terminate subsequently.
                } else {
                    item->u.stringValue = new AString(stringValue);
                }
                break;
            }

            case kTypeMessage:
            {
                sp<AMessage> subMsg = AMessage::FromParcel(parcel);
                subMsg->incStrong(msg.get());

                item->u.refValue = subMsg.get();
                break;
            }

            default:
            {
                ALOGE("This type of object cannot cross process boundaries.");
                TRESPASS();
            }
        }
    }

    return msg;
}

void AMessage::writeToParcel(Parcel *parcel) const {
    parcel->writeInt32(static_cast<int32_t>(mWhat));
    parcel->writeInt32(static_cast<int32_t>(mNumItems));

    for (size_t i = 0; i < mNumItems; ++i) {
        const Item &item = mItems[i];

        parcel->writeCString(item.mName);
        parcel->writeInt32(static_cast<int32_t>(item.mType));

        switch (item.mType) {
            case kTypeInt32:
            {
                parcel->writeInt32(item.u.int32Value);
                break;
            }

            case kTypeInt64:
            {
                parcel->writeInt64(item.u.int64Value);
                break;
            }

            case kTypeSize:
            {
                parcel->writeInt32(static_cast<int32_t>(item.u.sizeValue));
                break;
            }

            case kTypeFloat:
            {
                parcel->writeFloat(item.u.floatValue);
                break;
            }

            case kTypeDouble:
            {
                parcel->writeDouble(item.u.doubleValue);
                break;
            }

            case kTypeString:
            {
                parcel->writeCString(item.u.stringValue->c_str());
                break;
            }

            case kTypeMessage:
            {
                static_cast<AMessage *>(item.u.refValue)->writeToParcel(parcel);
                break;
            }

            default:
            {
                ALOGE("This type of object cannot cross process boundaries.");
                TRESPASS();
            }
        }
    }
}

size_t AMessage::countEntries() const {
    return mNumItems;
}

const char *AMessage::getEntryNameAt(size_t index, Type *type) const {
    if (index >= mNumItems) {
        *type = kTypeInt32;

        return NULL;
    }

    *type = mItems[index].mType;

    return mItems[index].mName;
}

}  // namespace android