delta_base_cache: use list.h for LRU
[git/debian.git] / run-command.h
blob50666497aeca8f4d3d403cfaeb0afeb350216a42
1 #ifndef RUN_COMMAND_H
2 #define RUN_COMMAND_H
4 #ifndef NO_PTHREADS
5 #include <pthread.h>
6 #endif
8 #include "argv-array.h"
10 struct child_process {
11 const char **argv;
12 struct argv_array args;
13 struct argv_array env_array;
14 pid_t pid;
16 * Using .in, .out, .err:
17 * - Specify 0 for no redirections (child inherits stdin, stdout,
18 * stderr from parent).
19 * - Specify -1 to have a pipe allocated as follows:
20 * .in: returns the writable pipe end; parent writes to it,
21 * the readable pipe end becomes child's stdin
22 * .out, .err: returns the readable pipe end; parent reads from
23 * it, the writable pipe end becomes child's stdout/stderr
24 * The caller of start_command() must close the returned FDs
25 * after it has completed reading from/writing to it!
26 * - Specify > 0 to set a channel to a particular FD as follows:
27 * .in: a readable FD, becomes child's stdin
28 * .out: a writable FD, becomes child's stdout/stderr
29 * .err: a writable FD, becomes child's stderr
30 * The specified FD is closed by start_command(), even in case
31 * of errors!
33 int in;
34 int out;
35 int err;
36 const char *dir;
37 const char *const *env;
38 unsigned no_stdin:1;
39 unsigned no_stdout:1;
40 unsigned no_stderr:1;
41 unsigned git_cmd:1; /* if this is to be git sub-command */
42 unsigned silent_exec_failure:1;
43 unsigned stdout_to_stderr:1;
44 unsigned use_shell:1;
45 unsigned clean_on_exit:1;
48 #define CHILD_PROCESS_INIT { NULL, ARGV_ARRAY_INIT, ARGV_ARRAY_INIT }
49 void child_process_init(struct child_process *);
50 void child_process_clear(struct child_process *);
52 int start_command(struct child_process *);
53 int finish_command(struct child_process *);
54 int finish_command_in_signal(struct child_process *);
55 int run_command(struct child_process *);
58 * Returns the path to the hook file, or NULL if the hook is missing
59 * or disabled. Note that this points to static storage that will be
60 * overwritten by further calls to find_hook and run_hook_*.
62 extern const char *find_hook(const char *name);
63 LAST_ARG_MUST_BE_NULL
64 extern int run_hook_le(const char *const *env, const char *name, ...);
65 extern int run_hook_ve(const char *const *env, const char *name, va_list args);
67 #define RUN_COMMAND_NO_STDIN 1
68 #define RUN_GIT_CMD 2 /*If this is to be git sub-command */
69 #define RUN_COMMAND_STDOUT_TO_STDERR 4
70 #define RUN_SILENT_EXEC_FAILURE 8
71 #define RUN_USING_SHELL 16
72 #define RUN_CLEAN_ON_EXIT 32
73 int run_command_v_opt(const char **argv, int opt);
76 * env (the environment) is to be formatted like environ: "VAR=VALUE".
77 * To unset an environment variable use just "VAR".
79 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
81 /**
82 * Execute the given command, sending "in" to its stdin, and capturing its
83 * stdout and stderr in the "out" and "err" strbufs. Any of the three may
84 * be NULL to skip processing.
86 * Returns -1 if starting the command fails or reading fails, and otherwise
87 * returns the exit code of the command. Any output collected in the
88 * buffers is kept even if the command returns a non-zero exit. The hint fields
89 * gives starting sizes for the strbuf allocations.
91 * The fields of "cmd" should be set up as they would for a normal run_command
92 * invocation. But note that there is no need to set the in, out, or err
93 * fields; pipe_command handles that automatically.
95 int pipe_command(struct child_process *cmd,
96 const char *in, size_t in_len,
97 struct strbuf *out, size_t out_hint,
98 struct strbuf *err, size_t err_hint);
101 * Convenience wrapper around pipe_command for the common case
102 * of capturing only stdout.
104 static inline int capture_command(struct child_process *cmd,
105 struct strbuf *out,
106 size_t hint)
108 return pipe_command(cmd, NULL, 0, out, hint, NULL, 0);
112 * The purpose of the following functions is to feed a pipe by running
113 * a function asynchronously and providing output that the caller reads.
115 * It is expected that no synchronization and mutual exclusion between
116 * the caller and the feed function is necessary so that the function
117 * can run in a thread without interfering with the caller.
119 struct async {
121 * proc reads from in; closes it before return
122 * proc writes to out; closes it before return
123 * returns 0 on success, non-zero on failure
125 int (*proc)(int in, int out, void *data);
126 void *data;
127 int in; /* caller writes here and closes it */
128 int out; /* caller reads from here and closes it */
129 #ifdef NO_PTHREADS
130 pid_t pid;
131 #else
132 pthread_t tid;
133 int proc_in;
134 int proc_out;
135 #endif
136 int isolate_sigpipe;
139 int start_async(struct async *async);
140 int finish_async(struct async *async);
141 int in_async(void);
142 void NORETURN async_exit(int code);
145 * This callback should initialize the child process and preload the
146 * error channel if desired. The preloading of is useful if you want to
147 * have a message printed directly before the output of the child process.
148 * pp_cb is the callback cookie as passed to run_processes_parallel.
149 * You can store a child process specific callback cookie in pp_task_cb.
151 * Even after returning 0 to indicate that there are no more processes,
152 * this function will be called again until there are no more running
153 * child processes.
155 * Return 1 if the next child is ready to run.
156 * Return 0 if there are currently no more tasks to be processed.
157 * To send a signal to other child processes for abortion,
158 * return the negative signal number.
160 typedef int (*get_next_task_fn)(struct child_process *cp,
161 struct strbuf *out,
162 void *pp_cb,
163 void **pp_task_cb);
166 * This callback is called whenever there are problems starting
167 * a new process.
169 * You must not write to stdout or stderr in this function. Add your
170 * message to the strbuf out instead, which will be printed without
171 * messing up the output of the other parallel processes.
173 * pp_cb is the callback cookie as passed into run_processes_parallel,
174 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
176 * Return 0 to continue the parallel processing. To abort return non zero.
177 * To send a signal to other child processes for abortion, return
178 * the negative signal number.
180 typedef int (*start_failure_fn)(struct strbuf *out,
181 void *pp_cb,
182 void *pp_task_cb);
185 * This callback is called on every child process that finished processing.
187 * You must not write to stdout or stderr in this function. Add your
188 * message to the strbuf out instead, which will be printed without
189 * messing up the output of the other parallel processes.
191 * pp_cb is the callback cookie as passed into run_processes_parallel,
192 * pp_task_cb is the callback cookie as passed into get_next_task_fn.
194 * Return 0 to continue the parallel processing. To abort return non zero.
195 * To send a signal to other child processes for abortion, return
196 * the negative signal number.
198 typedef int (*task_finished_fn)(int result,
199 struct strbuf *out,
200 void *pp_cb,
201 void *pp_task_cb);
204 * Runs up to n processes at the same time. Whenever a process can be
205 * started, the callback get_next_task_fn is called to obtain the data
206 * required to start another child process.
208 * The children started via this function run in parallel. Their output
209 * (both stdout and stderr) is routed to stderr in a manner that output
210 * from different tasks does not interleave.
212 * start_failure_fn and task_finished_fn can be NULL to omit any
213 * special handling.
215 int run_processes_parallel(int n,
216 get_next_task_fn,
217 start_failure_fn,
218 task_finished_fn,
219 void *pp_cb);
221 #endif