Decodes a header block from the given buffer to the given callback.

Suppose a header block is represented by a sequence of ByteBuffers in the form of Iterator<ByteBuffer>. And the consumer of decoded headers is represented by the callback. Then to decode the header block, the following approach might be used:

while (buffers.hasNext()) {
    ByteBuffer input = buffers.next();
    decoder.decode(input, callback, !buffers.hasNext());
}

The decoder reads as much as possible of the header block from the given buffer, starting at the buffer's position, and increments its position to reflect the bytes read. The buffer's mark and limit will not be modified.

Once the method is invoked with endOfHeaderBlock == true, the current header block is deemed ended, and inconsistencies, if any, are reported immediately by throwing an UncheckedIOException.

Each callback method is called only after the implementation has processed the corresponding bytes. If the bytes revealed a decoding error, the callback method is not called.

In addition to exceptions thrown directly by the method, any exceptions thrown from the callback will bubble up. The method asks for endOfHeaderBlock flag instead of returning it for two reasons. The first one is that the user of the decoder always knows which chunk is the last. The second one is to throw the most detailed exception possible, which might be useful for diagnosing issues. This implementation is not atomic in respect to decoding errors. In other words, if the decoding operation has thrown a decoding error, the decoder is no longer usable.

Parameters

headerBlockChunk:Buffer

the chunk of the header block, may be empty

finalChunk:boolean

true if the chunk is the final (or the only one) in the sequence

consumer:DecodingCallback

the callback

Exceptions

RuntimeException:

in case of a decoding error

NullPointerException:

if either headerBlock or consumer are null

Sets a maximum capacity of the header table.

The value has to be agreed between decoder and encoder out-of-band, e.g. by a protocol that uses HPACK (see 4.2. Maximum Table Size).

Parameters

capacity:int

a non-negative integer

Exceptions

IllegalArgumentException:

if capacity is negative