diff options
| -rw-r--r-- | util/path.c | 193 |
1 files changed, 43 insertions, 150 deletions
diff --git a/util/path.c b/util/path.c index 7f9fc272fb..8e174eb436 100644 --- a/util/path.c +++ b/util/path.c @@ -8,170 +8,63 @@ #include <dirent.h> #include "qemu/cutils.h" #include "qemu/path.h" +#include "qemu/thread.h" -struct pathelem -{ - /* Name of this, eg. lib */ - char *name; - /* Full path name, eg. /usr/gnemul/x86-linux/lib. */ - char *pathname; - struct pathelem *parent; - /* Children */ - unsigned int num_entries; - struct pathelem *entries[0]; -}; - -static struct pathelem *base; - -/* First N chars of S1 match S2, and S2 is N chars long. */ -static int strneq(const char *s1, unsigned int n, const char *s2) -{ - unsigned int i; - - for (i = 0; i < n; i++) - if (s1[i] != s2[i]) - return 0; - return s2[i] == 0; -} - -static struct pathelem *add_entry(struct pathelem *root, const char *name, - unsigned type); +static const char *base; +static GHashTable *hash; +static QemuMutex lock; -static struct pathelem *new_entry(const char *root, - struct pathelem *parent, - const char *name) -{ - struct pathelem *new = g_malloc(sizeof(*new)); - new->name = g_strdup(name); - new->pathname = g_strdup_printf("%s/%s", root, name); - new->num_entries = 0; - return new; -} - -#define streq(a,b) (strcmp((a), (b)) == 0) - -/* Not all systems provide this feature */ -#if defined(DT_DIR) && defined(DT_UNKNOWN) && defined(DT_LNK) -# define dirent_type(dirent) ((dirent)->d_type) -# define is_dir_maybe(type) \ - ((type) == DT_DIR || (type) == DT_UNKNOWN || (type) == DT_LNK) -#else -# define dirent_type(dirent) (1) -# define is_dir_maybe(type) (type) -#endif - -static struct pathelem *add_dir_maybe(struct pathelem *path) +void init_paths(const char *prefix) { - DIR *dir; - - if ((dir = opendir(path->pathname)) != NULL) { - struct dirent *dirent; - - while ((dirent = readdir(dir)) != NULL) { - if (!streq(dirent->d_name,".") && !streq(dirent->d_name,"..")){ - path = add_entry(path, dirent->d_name, dirent_type(dirent)); - } - } - closedir(dir); + if (prefix[0] == '\0' || !strcmp(prefix, "/")) { + return; } - return path; -} - -static struct pathelem *add_entry(struct pathelem *root, const char *name, - unsigned type) -{ - struct pathelem **e; - - root->num_entries++; - - root = g_realloc(root, sizeof(*root) - + sizeof(root->entries[0])*root->num_entries); - e = &root->entries[root->num_entries-1]; - *e = new_entry(root->pathname, root, name); - if (is_dir_maybe(type)) { - *e = add_dir_maybe(*e); + if (prefix[0] == '/') { + base = g_strdup(prefix); + } else { + char *cwd = g_get_current_dir(); + base = g_build_filename(cwd, prefix, NULL); + g_free(cwd); } - return root; -} - -/* This needs to be done after tree is stabilized (ie. no more reallocs!). */ -static void set_parents(struct pathelem *child, struct pathelem *parent) -{ - unsigned int i; - - child->parent = parent; - for (i = 0; i < child->num_entries; i++) - set_parents(child->entries[i], child); + hash = g_hash_table_new(g_str_hash, g_str_equal); + qemu_mutex_init(&lock); } -/* FIXME: Doesn't handle DIR/.. where DIR is not in emulated dir. */ -static const char * -follow_path(const struct pathelem *cursor, const char *name) -{ - unsigned int i, namelen; - - name += strspn(name, "/"); - namelen = strcspn(name, "/"); - - if (namelen == 0) - return cursor->pathname; - - if (strneq(name, namelen, "..")) - return follow_path(cursor->parent, name + namelen); - - if (strneq(name, namelen, ".")) - return follow_path(cursor, name + namelen); - - for (i = 0; i < cursor->num_entries; i++) - if (strneq(name, namelen, cursor->entries[i]->name)) - return follow_path(cursor->entries[i], name + namelen); - - /* Not found */ - return NULL; -} - -void init_paths(const char *prefix) +/* Look for path in emulation dir, otherwise return name. */ +const char *path(const char *name) { - char pref_buf[PATH_MAX]; - - if (prefix[0] == '\0' || - !strcmp(prefix, "/")) - return; + gpointer key, value; + const char *ret; - if (prefix[0] != '/') { - char *cwd = getcwd(NULL, 0); - size_t pref_buf_len = sizeof(pref_buf); + /* Only do absolute paths: quick and dirty, but should mostly be OK. */ + if (!base || !name || name[0] != '/') { + return name; + } - if (!cwd) - abort(); - pstrcpy(pref_buf, sizeof(pref_buf), cwd); - pstrcat(pref_buf, pref_buf_len, "/"); - pstrcat(pref_buf, pref_buf_len, prefix); - free(cwd); - } else - pstrcpy(pref_buf, sizeof(pref_buf), prefix + 1); + qemu_mutex_lock(&lock); - base = new_entry("", NULL, pref_buf); - base = add_dir_maybe(base); - if (base->num_entries == 0) { - g_free(base->pathname); - g_free(base->name); - g_free(base); - base = NULL; + /* Have we looked up this file before? */ + if (g_hash_table_lookup_extended(hash, name, &key, &value)) { + ret = value ? value : name; } else { - set_parents(base, base); + char *save = g_strdup(name); + char *full = g_build_filename(base, name, NULL); + + /* Look for the path; record the result, pass or fail. */ + if (access(full, F_OK) == 0) { + /* Exists. */ + g_hash_table_insert(hash, save, full); + ret = full; + } else { + /* Does not exist. */ + g_free(full); + g_hash_table_insert(hash, save, NULL); + ret = name; + } } -} - -/* Look for path in emulation dir, otherwise return name. */ -const char *path(const char *name) -{ - /* Only do absolute paths: quick and dirty, but should mostly be OK. - Could do relative by tracking cwd. */ - if (!base || !name || name[0] != '/') - return name; - return follow_path(base, name) ?: name; + qemu_mutex_unlock(&lock); + return ret; } |