From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- netwerk/protocol/http/README | 119 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 netwerk/protocol/http/README (limited to 'netwerk/protocol/http/README') diff --git a/netwerk/protocol/http/README b/netwerk/protocol/http/README new file mode 100644 index 000000000..621e9e950 --- /dev/null +++ b/netwerk/protocol/http/README @@ -0,0 +1,119 @@ + Darin Fisher + darin@netscape.com + 8/8/2001 + + HTTP DESIGN NOTES + + +CLASS BREAKDOWN + + nsHttpHandler + - implements nsIProtocolHandler + - manages preferences + - owns the authentication cache + - holds references to frequently used services + + nsHttpChannel + - implements nsIHttpChannel + - talks to the cache + - initiates http transactions + - processes http response codes + - intercepts progress notifications + + nsHttpConnection + - implements nsIStreamListener & nsIStreamProvider + - talks to the socket transport service + - feeds data to its transaction object + - routes progress notifications + + nsHttpConnectionInfo + - identifies a connection + + nsHttpTransaction + - implements nsIRequest + - encapsulates a http request and response + - parses incoming data + + nsHttpChunkedDecoder + - owned by a transaction + - removes chunked decoding + + nsHttpRequestHead + - owns a nsHttpHeaderArray + - knows how to fill a request buffer + + nsHttpResponseHead + - owns a nsHttpHeaderArray + - knows how to parse response lines + - performs common header manipulations/calculations + + nsHttpHeaderArray + - stores http "
:" pairs + + nsHttpAuthCache + - stores authentication credentials for http auth domains + + nsHttpBasicAuth + - implements nsIHttpAuthenticator + - generates BASIC auth credentials from user:pass + + +ATOMS + + nsHttp:: (header namespace) + + eg. nsHttp::Content_Length + + +TRANSACTION MODEL + + InitiateTransaction -> ActivateConnection -> AsyncWrite, AsyncRead + + The channel creates transactions, and passes them to the handler via + InitiateTransaction along with a nsHttpConnectionInfo object + identifying the requested connection. The handler either dispatches + the transaction immediately or queues it up to be dispatched later, + depending on whether or not the limit on the number of connections + to the requested server has been reached. Once the transaction can + be run, the handler looks for an idle connection or creates a new + connection, and then (re)activates the connection, assigning it the + new transaction. + + Once activated the connection ensures that it has a socket transport, + and then calls AsyncWrite and AsyncRead on the socket transport. This + begins the process of talking to the server. To minimize buffering, + socket transport thread-proxying is completely disabled (using the flags + DONT_PROXY_LISTENER | DONT_PROXY_PROVIDER | DONT_PROXY_OBSERVER with + both AsyncWrite and AsyncRead). This means that the nsHttpConnection's + OnStartRequest, OnDataAvailable, OnDataWritable, and OnStopRequest + methods will execute on the socket transport thread. + + The transaction defines (non-virtual) OnDataReadable, OnDataWritable, and + OnStopTransaction methods, which the connection calls in response to + its OnDataAvailable, OnDataWritable, and OnStopRequest methods, respectively. + The transaction owns a nsStreamListenerProxy created by the channel, which + it uses to transfer data from the socket thread over to the client's thread. + To mimize buffering, the transaction implements nsIInputStream, and passes + itself to the stream listener proxy's OnDataAvailable. In this way, we + have effectively wedged the response parsing between the socket and the + thread proxy's buffer. When read, the transaction turns around and reads + from the socket using the buffer passed to it. The transaction scans the + buffer for headers, removes them as they are detected, and copies the headers + into its nsHttpResponseHead object. The rest of the data remains in the + buffer, and is proxied over to the client's thread to be handled first by the + http channel and eventually by the client. + + There are several other major design factors, including: + + - transaction cancelation + - progress notification + - SSL tunneling + - chunked decoding + - thread safety + - premature EOF detection and transaction restarting + - pipelining (not yet implemented) + + +CACHING + + -- cgit v1.2.3