From 0576ea1010fd1be2d610cf57372f0ff5ee4ee003 Mon Sep 17 00:00:00 2001 From: Leah Neukirchen Date: Fri, 10 Nov 2017 16:08:43 +0100 Subject: replace use of (tsearch etc.) with own tree implementation tsearch(3) can be terribly inefficient on some systems, degrading to linear search. This AA-tree implementation is not measurably slower than e.g. musl's AVL tree implementation. Meanwhile, get rid of the silly tsearch API. --- lr.c | 369 ++++++++++++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 242 insertions(+), 127 deletions(-) (limited to 'lr.c') diff --git a/lr.c b/lr.c index f89dec1..ae19843 100644 --- a/lr.c +++ b/lr.c @@ -49,7 +49,6 @@ #include #include #include -#include #include #include #include @@ -78,6 +77,9 @@ #define PATH_MAX 4096 #endif +struct fitree; +struct idtree; + static int Bflag; static int Cflag; static char *Cflags[64]; @@ -98,8 +100,6 @@ static char *argv0; static char *format; static char *ordering; static struct expr *expr; -static void *root; // tree -static void *new_root; // tree static int prune; static size_t prefixl; static char input_delim = '\n'; @@ -115,15 +115,13 @@ static char long_format[] = "%M%x %n %u %g %s %\324F %\324R %p%F%l\n"; static char zero_format[] = "%p\\0"; static char stat_format[] = "%D %i %M %n %u %g %R %s \"%Ab %Ad %AT %AY\" \"%Tb %Td %TT %TY\" \"%Cb %Cd %CT %CY\" %b %p\n"; -static void *users; -static void *groups; -static void *filesystems; -static int scanned_filesystems; +static struct fitree *root; +static struct fitree *new_root; -struct idmap { - long id; - char *name; -}; +static struct idtree *users; +static struct idtree *groups; +static struct idtree *filesystems; +static int scanned_filesystems; static int need_stat; static int need_group; @@ -936,19 +934,86 @@ readlin(const char *p, const char *alt) return b; } -int -idorder(const void *a, const void *b) +//// AA-tree implementation, adapted from https://github.com/ccxvii/minilibs +struct idtree { + long id; + char *name; + struct idtree *left, *right; + int level; +}; + +static struct idtree idtree_sentinel = { 0, 0, &idtree_sentinel, &idtree_sentinel, 0 }; + +static struct idtree * +idtree_make(long id, char *name) { - struct idmap *ia = (struct idmap *)a; - struct idmap *ib = (struct idmap *)b; + struct idtree *node = malloc(sizeof (struct idtree)); + node->id = id; + node->name = name; + node->left = node->right = &idtree_sentinel; + node->level = 1; + return node; +} - if (ia->id == ib->id) - return 0; - else if (ia->id < ib->id) - return -1; - else - return 1; +char * +idtree_lookup(struct idtree *node, long id) +{ + if (node) { + while (node != &idtree_sentinel) { + if (id == node->id) + return node->name; + else if (id < node->id) + node = node->left; + else + node = node->right; + } + } + + return 0; +} + +static struct idtree * +idtree_skew(struct idtree *node) +{ + if (node->left->level == node->level) { + struct idtree *save = node; + node = node->left; + save->left = node->right; + node->right = save; + } + return node; +} + +static struct idtree * +idtree_split(struct idtree *node) +{ + if (node->right->right->level == node->level) { + struct idtree *save = node; + node = node->right; + save->right = node->left; + node->left = save; + node->level++; + } + return node; +} + +struct idtree * +idtree_insert(struct idtree *node, long id, char *name) +{ + if (node && node != &idtree_sentinel) { + if (id == node->id) + return node; + else if (id < node->id) + node->left = idtree_insert(node->left, id, name); + else + node->right = idtree_insert(node->right, id, name); + node = idtree_skew(node); + node = idtree_split(node); + return node; + } + return idtree_make(id, name); } +//// static char * strid(long id) @@ -961,47 +1026,41 @@ strid(long id) static char * groupname(gid_t gid) { - struct idmap key, **result; - key.id = gid; - key.name = 0; - - if (!(result = tfind(&key, &groups, idorder))) { - struct group *g = getgrgid(gid); - if (g) { - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = gid; - newkey->name = strdup(g->gr_name); - if ((int)strlen(g->gr_name) > gwid) - gwid = strlen(g->gr_name); - tsearch(newkey, &groups, idorder); - return newkey->name; - } + char *name = idtree_lookup(groups, gid); + + if (name) + return name; + + struct group *g = getgrgid(gid); + if (g) { + if ((int)strlen(g->gr_name) > gwid) + gwid = strlen(g->gr_name); + char *name = strdup(g->gr_name); + groups = idtree_insert(groups, gid, name); + return name; } - return result ? (*result)->name : strid(gid); + return strid(gid); } static char * username(uid_t uid) { - struct idmap key, **result; - key.id = uid; - key.name = 0; - - if (!(result = tfind(&key, &users, idorder))) { - struct passwd *p = getpwuid(uid); - if (p) { - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = uid; - newkey->name = strdup(p->pw_name); - if ((int)strlen(p->pw_name) > uwid) - uwid = strlen(p->pw_name); - tsearch(newkey, &users, idorder); - return newkey->name; - } + char *name = idtree_lookup(users, uid); + + if (name) + return name; + + struct passwd *p = getpwuid(uid); + if (p) { + if ((int)strlen(p->pw_name) > uwid) + uwid = strlen(p->pw_name); + char *name = strdup(p->pw_name); + users = idtree_insert(users, uid, name); + return name; } - - return result ? (*result)->name : strid(uid); + + return strid(uid); } #if defined(__linux__) || defined(__CYGWIN__) @@ -1025,11 +1084,8 @@ scan_filesystems() while ((mnt = getmntent(mtab))) { if (stat(mnt->mnt_dir, &st) < 0) continue; - - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = st.st_dev; - newkey->name = strdup(mnt->mnt_type); - tsearch(newkey, &filesystems, idorder); + filesystems = idtree_insert(filesystems, + st.st_dev, strdup(mnt->mnt_type)); }; endmntent(mtab); @@ -1052,11 +1108,8 @@ scan_filesystems() while (getmntent(mtab, &mnt) == 0) { if (stat(mnt.mnt_mountp, &st) < 0) continue; - - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = st.st_dev; - newkey->name = strdup(mnt.mnt_fstype); - tsearch(newkey, &filesystems, idorder); + filesystems = idtree_insert(filesystems, + st.st_dev, strdup(mnt->mnt_fstype)); }; fclose(mtab); @@ -1077,11 +1130,8 @@ scan_filesystems() while (i-- > 0) { if (stat(mnt->f_mntonname, &st) < 0) continue; - - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = st.st_dev; - newkey->name = strdup(mnt->f_fstypename); - tsearch(newkey, &filesystems, idorder); + filesystems = idtree_insert(filesystems, + st.st_dev, strdup(mnt->f_fstypename)); mnt++; }; @@ -1100,11 +1150,8 @@ scan_filesystems() while (i-- > 0) { if (stat(mnt->f_mntonname, &st) < 0) continue; - - struct idmap *newkey = malloc(sizeof (struct idmap)); - newkey->id = st.st_dev; - newkey->name = strdup(mnt->f_fstypename); - tsearch(newkey, &filesystems, idorder); + filesystems = idtree_insert(filesystems, + st.st_dev, strdup(mnt->f_fstypename)); mnt++; }; @@ -1121,18 +1168,17 @@ scan_filesystems() static char * fstype(dev_t devid) { - struct idmap key, **result; - key.id = devid; - key.name = 0; - if (!scanned_filesystems) scan_filesystems(); - result = tfind(&key, &filesystems, idorder); - if (result && (int)strlen((*result)->name) > fwid) - fwid = strlen((*result)->name); + char *name = idtree_lookup(filesystems, devid); + if (name) { + if ((int)strlen(name) > fwid) + fwid = strlen(name); + return name; + } - return result ? (*result)->name : strid(devid); + return strid(devid); } static char * @@ -1416,6 +1462,98 @@ order(const void *a, const void *b) return strcmp(fa->fpath, fb->fpath); } +static void +free_fi(struct fileinfo *fi) +{ + if (fi) + free(fi->fpath); + free(fi); +} + +//// AA-tree implementation, adapted from https://github.com/ccxvii/minilibs +struct fitree { + struct fileinfo *fi; + struct fitree *left, *right; + int level; +}; + +static struct fitree fitree_sentinel = { 0, &fitree_sentinel, &fitree_sentinel, 0 }; + +static struct fitree * +fitree_make(struct fileinfo *fi) +{ + struct fitree *node = malloc(sizeof (struct fitree)); + node->fi = fi; + node->left = node->right = &fitree_sentinel; + node->level = 1; + return node; +} + +static struct fitree * +fitree_skew(struct fitree *node) +{ + if (node->left->level == node->level) { + struct fitree *save = node; + node = node->left; + save->left = node->right; + node->right = save; + } + return node; +} + +static struct fitree * +fitree_split(struct fitree *node) +{ + if (node->right->right->level == node->level) { + struct fitree *save = node; + node = node->right; + save->right = node->left; + node->left = save; + node->level++; + } + return node; +} + +struct fitree * +fitree_insert(struct fitree *node, struct fileinfo *fi) +{ + if (node && node != &fitree_sentinel) { + int c = order(fi, node->fi); + if (c == 0) + return node; + if (c < 0) + node->left = fitree_insert(node->left, fi); + else + node->right = fitree_insert(node->right, fi); + node = fitree_skew(node); + node = fitree_split(node); + return node; + } + return fitree_make(fi); +} + +void +fitree_walk(struct fitree *node, void (*visit)(struct fileinfo *)) +{ + if (node->left != &fitree_sentinel) + fitree_walk(node->left, visit); + visit(node->fi); + if (node->right != &fitree_sentinel) + fitree_walk(node->right, visit); +} + +void +fitree_free(struct fitree *node) +{ + if (node && node != &fitree_sentinel) { + fitree_free(node->left); + fitree_free(node->right); + free_fi(node->fi); + free(node); + } +} +//// + static int intlen(intmax_t i) { @@ -1859,22 +1997,7 @@ print_format(struct fileinfo *fi) } } -void -tree_print(const void *nodep, const VISIT which, const int depth) -{ - (void)depth; - - if (which == postorder || which == leaf) - print_format(*(struct fileinfo **)nodep); -} - -static void -free_fi(struct fileinfo *fi) -{ - if (fi) - free(fi->fpath); - free(fi); -} +static int initial; int callback(const char *fpath, const struct stat *sb, int depth, ino_t entries, off_t total) @@ -1904,10 +2027,16 @@ callback(const char *fpath, const struct stat *sb, int depth, ino_t entries, off print_format(fi); free_fi(fi); } else if (Bflag) { - tsearch(fi, depth > 0 ? &new_root : &root, order); + if (initial) { + if (fi->depth == 0) + root = fitree_insert(root, fi); + } else { + if (fi->depth == bflag_depth + 1) + new_root = fitree_insert(new_root, fi); + } } else { - // add to the tree, note that this will elimnate duplicate files - tsearch(fi, &root, order); + // add to the tree, note that this will eliminate duplicate files + root = fitree_insert(root, fi); } if (depth > maxdepth) @@ -2062,30 +2191,14 @@ recurse(char *path, struct history *h, int guessdir) } void -tree_recurse(const void *nodep, const VISIT which, const int depth) +tree_recurse(struct fileinfo *fi) { - struct fileinfo *fi = *((struct fileinfo **)nodep); + if (S_ISDIR(fi->sb.st_mode)) { + char path[PATH_MAX]; - (void)depth; - - if (which == postorder || which == leaf) { - if (S_ISDIR(fi->sb.st_mode)) { - char path[PATH_MAX]; - - strcpy(path, fi->fpath); - bflag_depth = fi->depth; - recurse(path, 0, 0); - } - } -} - -void -tree_free() -{ - while (root) { - struct fileinfo *fi = *(struct fileinfo **)root; - tdelete(fi, &root, order); - free_fi(fi); + strcpy(path, fi->fpath); + bflag_depth = fi->depth; + recurse(path, 0, 0); } } @@ -2260,24 +2373,26 @@ main(int argc, char *argv[]) current_color = -1; + initial = 1; if (!Cflag && optind == argc) { traverse(""); } else { for (i = optind; i < argc; i++) traverse(argv[i]); } + initial = 0; if (Bflag) { while (root) { - twalk(root, tree_print); - twalk(root, tree_recurse); - tree_free(); + fitree_walk(root, print_format); + fitree_walk(root, tree_recurse); + fitree_free(root); root = new_root; new_root = 0; } } else if (!Uflag) { - twalk(root, tree_print); + fitree_walk(root, print_format); // no need to destroy here, we are done } -- cgit 1.4.1