From 689d0650ab63425adaea26afe347015a204958ee Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 1 Oct 2020 21:52:16 +0200 Subject: libbb: shrink recursive_action() by reducing memory pressure function old new delta recursive_action1 - 316 +316 file_action_grep 161 164 +3 add_to_prg_cache_if_socket 202 205 +3 depmod_main 509 511 +2 writeFileToTarball 488 489 +1 parse_module 281 282 +1 fileAction 207 208 +1 act 189 190 +1 add_to_dirlist 65 64 -1 writeTarFile 196 194 -2 uuidcache_init 47 45 -2 uuidcache_check_device 109 107 -2 true_action 8 6 -2 run_parts_main 310 308 -2 netstat_main 534 532 -2 lsusb_main 29 27 -2 lspci_main 45 43 -2 initial_scan 138 136 -2 grep_main 845 843 -2 find_main 482 480 -2 config_file_action 437 435 -2 chmod_main 142 140 -2 dirAction 14 10 -4 diff_main 1544 1540 -4 chown_main 154 148 -6 skip_dir 136 129 -7 dir_act 191 184 -7 recursive_action 453 69 -384 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 7/20 up/down: 328/-439) Total: -111 bytes Signed-off-by: Denys Vlasenko --- libbb/recursive_action.c | 72 +++++++++++++++++++++++++++++------------------- 1 file changed, 43 insertions(+), 29 deletions(-) (limited to 'libbb') diff --git a/libbb/recursive_action.c b/libbb/recursive_action.c index 0831ecc3a..b1c4bfad7 100644 --- a/libbb/recursive_action.c +++ b/libbb/recursive_action.c @@ -21,10 +21,9 @@ * is so stinking huge. */ -static int FAST_FUNC true_action(const char *fileName UNUSED_PARAM, - struct stat *statbuf UNUSED_PARAM, - void* userData UNUSED_PARAM, - int depth UNUSED_PARAM) +static int FAST_FUNC true_action(struct recursive_state *state UNUSED_PARAM, + const char *fileName UNUSED_PARAM, + struct stat *statbuf UNUSED_PARAM) { return TRUE; } @@ -65,12 +64,7 @@ static int FAST_FUNC true_action(const char *fileName UNUSED_PARAM, * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir. */ -int FAST_FUNC recursive_action(const char *fileName, - unsigned flags, - int FAST_FUNC (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth), - int FAST_FUNC (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth), - void* userData, - unsigned depth) +static int recursive_action1(recursive_state_t *state, const char *fileName) { struct stat statbuf; unsigned follow; @@ -78,24 +72,21 @@ int FAST_FUNC recursive_action(const char *fileName, DIR *dir; struct dirent *next; - if (!fileAction) fileAction = true_action; - if (!dirAction) dirAction = true_action; - follow = ACTION_FOLLOWLINKS; - if (depth == 0) + if (state->depth == 0) follow = ACTION_FOLLOWLINKS | ACTION_FOLLOWLINKS_L0; - follow &= flags; + follow &= state->flags; status = (follow ? stat : lstat)(fileName, &statbuf); if (status < 0) { #ifdef DEBUG_RECURS_ACTION - bb_error_msg("status=%d flags=%x", status, flags); + bb_error_msg("status=%d flags=%x", status, state->flags); #endif - if ((flags & ACTION_DANGLING_OK) + if ((state->flags & ACTION_DANGLING_OK) && errno == ENOENT && lstat(fileName, &statbuf) == 0 ) { /* Dangling link */ - return fileAction(fileName, &statbuf, userData, depth); + return state->fileAction(state, fileName, &statbuf); } goto done_nak_warn; } @@ -103,20 +94,20 @@ int FAST_FUNC recursive_action(const char *fileName, /* If S_ISLNK(m), then we know that !S_ISDIR(m). * Then we can skip checking first part: if it is true, then * (!dir) is also true! */ - if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */ + if ( /* (!(state->flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */ !S_ISDIR(statbuf.st_mode) ) { - return fileAction(fileName, &statbuf, userData, depth); + return state->fileAction(state, fileName, &statbuf); } /* It's a directory (or a link to one, and followLinks is set) */ - if (!(flags & ACTION_RECURSE)) { - return dirAction(fileName, &statbuf, userData, depth); + if (!(state->flags & ACTION_RECURSE)) { + return state->dirAction(state, fileName, &statbuf); } - if (!(flags & ACTION_DEPTHFIRST)) { - status = dirAction(fileName, &statbuf, userData, depth); + if (!(state->flags & ACTION_DEPTHFIRST)) { + status = state->dirAction(state, fileName, &statbuf); if (status == FALSE) goto done_nak_warn; if (status == SKIP) @@ -140,11 +131,13 @@ int FAST_FUNC recursive_action(const char *fileName, continue; /* process every file (NB: ACTION_RECURSE is set in flags) */ - s = recursive_action(nextFile, flags, fileAction, dirAction, - userData, depth + 1); + state->depth++; + s = recursive_action1(state, nextFile); if (s == FALSE) status = FALSE; free(nextFile); + state->depth--; + //#define RECURSE_RESULT_ABORT -1 // if (s == RECURSE_RESULT_ABORT) { // closedir(dir); @@ -153,15 +146,36 @@ int FAST_FUNC recursive_action(const char *fileName, } closedir(dir); - if (flags & ACTION_DEPTHFIRST) { - if (!dirAction(fileName, &statbuf, userData, depth)) + if (state->flags & ACTION_DEPTHFIRST) { + if (!state->dirAction(state, fileName, &statbuf)) goto done_nak_warn; } return status; done_nak_warn: - if (!(flags & ACTION_QUIET)) + if (!(state->flags & ACTION_QUIET)) bb_simple_perror_msg(fileName); return FALSE; } + +int FAST_FUNC recursive_action(const char *fileName, + unsigned flags, + int FAST_FUNC (*fileAction)(struct recursive_state *state, const char *fileName, struct stat* statbuf), + int FAST_FUNC (*dirAction)(struct recursive_state *state, const char *fileName, struct stat* statbuf), + void *userData) +{ + /* Keeping a part of variables of recusive descent in a "state structure" + * instead of passing ALL of them down as parameters of recursive_action1() + * relieves register pressure, both in recursive_action1() + * and in every file/dirAction(). + */ + recursive_state_t state; + state.flags = flags; + state.depth = 0; + state.userData = userData; + state.fileAction = fileAction ? fileAction : true_action; + state.dirAction = dirAction ? dirAction : true_action; + + return recursive_action1(&state, fileName); +} -- cgit v1.2.3