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authorVincent Ambo <Vincent Ambo>2020-01-11T23·36+0000
committerVincent Ambo <Vincent Ambo>2020-01-11T23·40+0000
commit7ef0d62730840ded097b524104cc0a0904591a63 (patch)
treea670f96103667aeca4789a95d94ca0dff550c4ce /third_party/git/Documentation/technical/long-running-process-protocol.txt
parent6a2a3007077818e24a3d56fc492ada9206a10cf0 (diff)
parent1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 (diff)
merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373
Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'
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+Long-running process protocol
+=============================
+
+This protocol is used when Git needs to communicate with an external
+process throughout the entire life of a single Git command. All
+communication is in pkt-line format (see technical/protocol-common.txt)
+over standard input and standard output.
+
+Handshake
+---------
+
+Git starts by sending a welcome message (for example,
+"git-filter-client"), a list of supported protocol version numbers, and
+a flush packet. Git expects to read the welcome message with "server"
+instead of "client" (for example, "git-filter-server"), exactly one
+protocol version number from the previously sent list, and a flush
+packet. All further communication will be based on the selected version.
+The remaining protocol description below documents "version=2". Please
+note that "version=42" in the example below does not exist and is only
+there to illustrate how the protocol would look like with more than one
+version.
+
+After the version negotiation Git sends a list of all capabilities that
+it supports and a flush packet. Git expects to read a list of desired
+capabilities, which must be a subset of the supported capabilities list,
+and a flush packet as response:
+------------------------
+packet:          git> git-filter-client
+packet:          git> version=2
+packet:          git> version=42
+packet:          git> 0000
+packet:          git< git-filter-server
+packet:          git< version=2
+packet:          git< 0000
+packet:          git> capability=clean
+packet:          git> capability=smudge
+packet:          git> capability=not-yet-invented
+packet:          git> 0000
+packet:          git< capability=clean
+packet:          git< capability=smudge
+packet:          git< 0000
+------------------------
+
+Shutdown
+--------
+
+Git will close
+the command pipe on exit. The filter is expected to detect EOF
+and exit gracefully on its own. Git will wait until the filter
+process has stopped.