C++ ZipEntry::initFromCDE方法代码示例

//.........这里部分代码省略.........
    /* read the last part of the file into the buffer */
    if (fread(buf, 1, readAmount, mZipFp) != (size_t) readAmount) {
        LOGD("short file? wanted %ld\n", readAmount);
        result = UNKNOWN_ERROR;
        goto bail;
    }

    /* find the end-of-central-dir magic */
    for (i = readAmount - 4; i >= 0; i--) {
        if (buf[i] == 0x50 &&
            ZipEntry::getLongLE(&buf[i]) == EndOfCentralDir::kSignature)
        {
            LOGV("+++ Found EOCD at buf+%d\n", i);
            break;
        }
    }
    if (i < 0) {
        LOGD("EOCD not found, not Zip\n");
        result = INVALID_OPERATION;
        goto bail;
    }

    /* extract eocd values */
    result = mEOCD.readBuf(buf + i, readAmount - i);
    if (result != NO_ERROR) {
        LOGD("Failure reading %ld bytes of EOCD values", readAmount - i);
        goto bail;
    }
    //mEOCD.dump();

    if (mEOCD.mDiskNumber != 0 || mEOCD.mDiskWithCentralDir != 0 ||
        mEOCD.mNumEntries != mEOCD.mTotalNumEntries)
    {
        LOGD("Archive spanning not supported\n");
        result = INVALID_OPERATION;
        goto bail;
    }

    /*
     * So far so good.  "mCentralDirSize" is the size in bytes of the
     * central directory, so we can just seek back that far to find it.
     * We can also seek forward mCentralDirOffset bytes from the
     * start of the file.
     *
     * We're not guaranteed to have the rest of the central dir in the
     * buffer, nor are we guaranteed that the central dir will have any
     * sort of convenient size.  We need to skip to the start of it and
     * read the header, then the other goodies.
     *
     * The only thing we really need right now is the file comment, which
     * we're hoping to preserve.
     */
    if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0) {
        LOGD("Failure seeking to central dir offset %ld\n",
             mEOCD.mCentralDirOffset);
        result = UNKNOWN_ERROR;
        goto bail;
    }

    /*
     * Loop through and read the central dir entries.
     */
    LOGV("Scanning %d entries...\n", mEOCD.mTotalNumEntries);
    int entry;
    for (entry = 0; entry < mEOCD.mTotalNumEntries; entry++) {
        ZipEntry* pEntry = new ZipEntry;

        result = pEntry->initFromCDE(mZipFp);
        if (result != NO_ERROR) {
            LOGD("initFromCDE failed\n");
            delete pEntry;
            goto bail;
        }

        mEntries.add(pEntry);
    }


    /*
     * If all went well, we should now be back at the EOCD.
     */
    {
        unsigned char checkBuf[4];
        if (fread(checkBuf, 1, 4, mZipFp) != 4) {
            LOGD("EOCD check read failed\n");
            result = INVALID_OPERATION;
            goto bail;
        }
        if (ZipEntry::getLongLE(checkBuf) != EndOfCentralDir::kSignature) {
            LOGD("EOCD read check failed\n");
            result = UNKNOWN_ERROR;
            goto bail;
        }
        LOGV("+++ EOCD read check passed\n");
    }

bail:
    delete[] buf;
    return result;
}