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| #ifndef SUBPROCESS_H | |
| #define SUBPROCESS_H | |
| #include "git-compat-util.h" | |
| #include "hashmap.h" | |
| #include "run-command.h" | |
| /* | |
| * The sub-process API makes it possible to run background sub-processes | |
| * for the entire lifetime of a Git invocation. If Git needs to communicate | |
| * with an external process multiple times, then this can reduces the process | |
| * invocation overhead. Git and the sub-process communicate through stdin and | |
| * stdout. | |
| * | |
| * The sub-processes are kept in a hashmap by command name and looked up | |
| * via the subprocess_find_entry function. If an existing instance can not | |
| * be found then a new process should be created and started. When the | |
| * parent git command terminates, all sub-processes are also terminated. | |
| * | |
| * This API is based on the run-command API. | |
| */ | |
| /* data structures */ | |
| /* Members should not be accessed directly. */ | |
| struct subprocess_entry { | |
| struct hashmap_entry ent; | |
| const char *cmd; | |
| struct child_process process; | |
| }; | |
| struct subprocess_capability { | |
| const char *name; | |
| /* | |
| * subprocess_handshake will "|=" this value to supported_capabilities | |
| * if the server reports that it supports this capability. | |
| */ | |
| unsigned int flag; | |
| }; | |
| /* subprocess functions */ | |
| /* Function to test two subprocess hashmap entries for equality. */ | |
| int cmd2process_cmp(const void *unused_cmp_data, | |
| const struct hashmap_entry *e, | |
| const struct hashmap_entry *entry_or_key, | |
| const void *unused_keydata); | |
| /* | |
| * User-supplied function to initialize the sub-process. This is | |
| * typically used to negotiate the interface version and capabilities. | |
| */ | |
| typedef int(*subprocess_start_fn)(struct subprocess_entry *entry); | |
| /* Start a subprocess and add it to the subprocess hashmap. */ | |
| int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd, | |
| subprocess_start_fn startfn); | |
| /* Kill a subprocess and remove it from the subprocess hashmap. */ | |
| void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry); | |
| /* Find a subprocess in the subprocess hashmap. */ | |
| struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd); | |
| /* subprocess helper functions */ | |
| /* Get the underlying `struct child_process` from a subprocess. */ | |
| static inline struct child_process *subprocess_get_child_process( | |
| struct subprocess_entry *entry) | |
| { | |
| return &entry->process; | |
| } | |
| /* | |
| * Perform the version and capability negotiation as described in the | |
| * "Handshake" section of long-running-process-protocol.txt using the | |
| * given requested versions and capabilities. The "versions" and "capabilities" | |
| * parameters are arrays terminated by a 0 or blank struct. | |
| * | |
| * This function is typically called when a subprocess is started (as part of | |
| * the "startfn" passed to subprocess_start). | |
| */ | |
| int subprocess_handshake(struct subprocess_entry *entry, | |
| const char *welcome_prefix, | |
| int *versions, | |
| int *chosen_version, | |
| struct subprocess_capability *capabilities, | |
| unsigned int *supported_capabilities); | |
| /* | |
| * Helper function that will read packets looking for "status=<foo>" | |
| * key/value pairs and return the value from the last "status" packet | |
| */ | |
| int subprocess_read_status(int fd, struct strbuf *status); | |
| #endif |