hadoop 之 libhdfs

Hadoop 3.2.2

libhdfs/hdfs.c

struct hdfsFile_internal {
    void* file;
    enum hdfsStreamType type;
    int flags;
};
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以上数据结构中的 flags 是由以下接口赋值

hdfsFile hdfsOpenFile(hdfsFS fs, const char *path, int flags,
                      int bufferSize, short replication, tSize blockSize)
{
    struct hdfsStreamBuilder *bld = hdfsStreamBuilderAlloc(fs, path, flags);
    if (bufferSize != 0) {
      hdfsStreamBuilderSetBufferSize(bld, bufferSize);
    }
    if (replication != 0) {
      hdfsStreamBuilderSetReplication(bld, replication);
    }
    if (blockSize != 0) {
      hdfsStreamBuilderSetDefaultBlockSize(bld, blockSize);
    }
    return hdfsStreamBuilderBuild(bld);
}

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int hdfsFileUsesDirectRead(hdfsFile file)
{
    return !!(file->flags & HDFS_FILE_SUPPORTS_DIRECT_READ);
}

void hdfsFileDisableDirectRead(hdfsFile file)
{
    file->flags &= ~HDFS_FILE_SUPPORTS_DIRECT_READ;
}

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