108 lines
3.2 KiB
Markdown
108 lines
3.2 KiB
Markdown
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Overview
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--------
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"Chunked transfer encoding is a streaming data transfer mechanism available in version 1.1 of the Hypertext Transfer Protocol (HTTP). In chunked transfer encoding, the data stream is divided into a series of non-overlapping "chunks". The chunks are sent out and received independently of one another. No knowledge of the data stream outside the currently-being-processed chunk is necessary for both the sender and the receiver at any given time.
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Each chunk is preceded by its size in bytes. The transmission ends when a zero-length chunk is received. The chunked keyword in the Transfer-Encoding header is used to indicate chunked transfer." -- [Wikipedia](https://en.wikipedia.org/wiki/Chunked_transfer_encoding)
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Example
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-------
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```C++
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#include <string>
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#include <memory>
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#include <cstring>
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#include <cstdlib>
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#include <ciso646>
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#include <iostream>
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#include <restbed>
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using namespace std;
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using namespace restbed;
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void read_chunk_size( const shared_ptr< Session > session, const Bytes& data )
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{
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if ( not data.empty( ) )
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{
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const string length( data.begin( ), data.end( ) );
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if ( length not_eq "0\r\n" )
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{
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const auto chunk_size = stoul( length, nullptr, 16 ) + strlen( "\r\n" );
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session->fetch( chunk_size, read_chunk );
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return;
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}
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}
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session->close( OK );
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const auto request = session->get_request( );
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const auto body = request->get_body( );
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fprintf( stdout, "Complete body content: %.*s\n", static_cast< int >( body.size( ) ), body.data( ) );
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}
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void read_chunk( const shared_ptr< Session > session, const Bytes& data )
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{
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cout << "Partial body chunk: " << data.size( ) << " bytes" << endl;
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session->fetch( "\r\n", read_chunk_size );
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}
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void post_method_handler( const shared_ptr< Session > session )
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{
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const auto request = session->get_request( );
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if ( request->get_header( "Transfer-Encoding", String::lowercase ) == "chunked" )
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{
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session->fetch( "\r\n", read_chunk_size );
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}
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else if ( request->has_header( "Content-Length" ) )
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{
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int length = request->get_header( "Content-Length", 0 );
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session->fetch( length, [ ]( const shared_ptr< Session > session, const Bytes& )
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{
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const auto request = session->get_request( );
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const auto body = request->get_body( );
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fprintf( stdout, "Complete body content: %.*s\n", static_cast< int >( body.size( ) ), body.data( ) );
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session->close( OK );
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} );
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}
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else
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{
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session->close( BAD_REQUEST );
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}
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}
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int main( const int, const char** )
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{
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auto resource = make_shared< Resource >( );
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resource->set_path( "/resources" );
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resource->set_method_handler( "POST", post_method_handler );
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auto settings = make_shared< Settings >( );
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settings->set_port( 1984 );
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settings->set_default_header( "Connection", "close" );
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Service service;
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service.publish( resource );
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service.start( settings );
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return EXIT_SUCCESS;
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}
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```
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Build
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-----
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> $ clang++ -o example example.cpp -l restbed
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Execution
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---------
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> $ ./example
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>
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> $ curl -w'\n' -v -X POST --header "Transfer-Encoding: chunked" -d @<PATH TO LARGE FILE> 'http://localhost:1984/resources'
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