| #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 |