add the fastindex module

1 files changed, 380 insertions, 0 deletions

diff --git a/libs/fastindex/src/fastindex.c b/libs/fastindex/src/fastindex.c
new file mode 100644
index 000000000..ab78c0935
--- /dev/null
+++ b/libs/fastindex/src/fastindex.c
@@ -0,0 +1,380 @@
+/*
+ * fastindex - fast lua module indexing plugin
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/cdefs.h>
+
+#ifndef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE /* XXX: portability hack for timestamp */
+#endif
+
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <glob.h>
+
+#include <lualib.h>
+#include <lauxlib.h>
+#include "list.h"
+
+#define MODNAME        "fastindex"
+#define PATTERN        "/*.lua"
+#define DEFAULT_BUFLEN 1024
+
+//#define DEBUG 1
+
+#ifdef DEBUG
+#define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define DPRINTF(...) do {} while (0)
+#endif
+
+/**
+ * list_for_each_offset	-	iterate over a list, start with the provided pointer
+ * @pos:	the &struct list_head to use as a loop cursor.
+ * @head:	the head for your list.
+ */
+#define list_for_each_offset(pos, head, offset) \
+	for (pos = (offset)->next; pos != (offset); \
+	     pos = ((pos->next == (head)) && ((offset) != (head)) ? (head)->next : pos->next))
+
+static char *namespace = NULL;
+
+struct fastindex_entry {
+	struct list_head list;
+	time_t timestamp;
+	int checked;
+	char *name;
+};
+
+struct fastindex_pattern {
+	struct list_head list;
+	char pattern[];
+};
+
+struct fastindex {
+	lua_State *L;
+	int checked;
+	char *func;
+	struct list_head patterns;
+	struct list_head *last;
+	struct list_head entries;
+	int ofs;
+	char *buf;
+	int buflen;
+};
+
+static inline struct fastindex *
+to_fastindex(struct lua_State *L)
+{
+	struct fastindex *f;
+	lua_getfield(L, lua_upvalueindex(1), "__data");
+	f = lua_touserdata(L, -1);
+	lua_pop(L, 1);
+	return f;
+}
+
+static int
+fastindex_module(lua_State *L)
+{
+	const char *s;
+	s = luaL_checkstring(L, 1);
+
+	if (s) {
+		if (namespace)
+			free(namespace);
+		namespace = strdup(s);
+	}
+
+	return 0;
+}
+
+static struct fastindex_entry *
+find_entry(struct fastindex *f, char *name)
+{
+	struct list_head *p;
+
+	if (!f->last)
+		f->last = &f->entries;
+
+	list_for_each_offset(p, &f->entries, f->last) {
+		struct fastindex_entry *e;
+		e = container_of(p, struct fastindex_entry, list);
+		if (!strcmp(e->name, name))
+			return e;
+	}
+	return NULL;
+}
+
+static struct fastindex_entry *
+new_entry(struct fastindex *f, char *name)
+{
+	struct fastindex_entry *e;
+
+	e = malloc(sizeof(struct fastindex_entry));
+	if (!e)
+		goto error;
+
+	memset(e, 0, sizeof(struct fastindex_entry));
+	e->name = strdup(name);
+	if (!e->name) {
+		free(e);
+		goto error;
+	}
+	INIT_LIST_HEAD(&e->list);
+
+	return e;
+
+error:
+	return NULL;
+}
+
+static void free_entry(struct fastindex_entry *e)
+{
+	list_del(&e->list);
+	free(e->name);
+	free(e);
+}
+
+int bufferwriter(lua_State *L, const void *p, size_t sz, void *ud)
+{
+	struct fastindex *f = ud;
+
+	while (f->ofs + sz > f->buflen) {
+		char *b = f->buf;
+		f->buflen *= 2;
+		f->buf = realloc(f->buf, f->buflen);
+		if (!f->buf) {
+			free(b);
+			return 1;
+		}
+	}
+	memcpy(f->buf + f->ofs, p, sz);
+	f->ofs += sz;
+	return 0;
+}
+
+static void
+load_index(struct fastindex *f, struct fastindex_entry *e)
+{
+	lua_State *L;
+
+	DPRINTF("Loading module: %s\n", e->name);
+
+	if (!f->buf)
+		f->buf = malloc(f->buflen);
+
+	if (!f->buf)
+		luaL_error(f->L, "Out of memory!\n");
+
+	f->ofs = 0;
+	L = luaL_newstate();
+	if (!L)
+		return;
+
+	namespace = NULL;
+	luaL_openlibs(L);
+	lua_pushcfunction(L, fastindex_module);
+	lua_setfield(L, LUA_GLOBALSINDEX, "module");
+
+	do {
+		if (luaL_dofile(L, e->name)) {
+			DPRINTF("Warning: unable to open module '%s'\n", e->name);
+			break;
+		}
+
+		lua_getglobal(L, f->func);
+		lua_dump(L, bufferwriter, f);
+		DPRINTF("Got %d bytes\n", f->ofs);
+		if (f->ofs == 0)
+			break;
+		lua_createtable(f->L, (namespace ? 2 : 1), 0);
+		luaL_loadbuffer(f->L, f->buf, f->ofs, "tmp");
+		lua_rawseti(f->L, -2, 1);
+		if (namespace) {
+			DPRINTF("Module has namespace '%s'\n", namespace);
+			lua_pushstring(f->L, namespace);
+			lua_rawseti(f->L, -2, 2);
+			free(namespace);
+			namespace = NULL;
+		}
+		lua_setfield(f->L, -2, e->name);
+	} while (0);
+
+	lua_close(L);
+}
+
+
+static int
+fastindex_scan(lua_State *L)
+{
+	struct list_head *tmp, *p;
+	struct fastindex *f;
+	glob_t gl;
+	int i;
+	int gl_flags = GLOB_NOESCAPE | GLOB_NOSORT | GLOB_MARK;
+
+	f = to_fastindex(L);
+	f->checked++;
+
+
+	if (list_empty(&f->patterns))
+		return 0;
+
+	lua_getfield(L, lua_upvalueindex(1), "indexes");
+	list_for_each(p, &f->patterns) {
+		struct fastindex_pattern *pt = container_of(p, struct fastindex_pattern, list);
+		glob(pt->pattern, gl_flags, NULL, &gl);
+		gl_flags |= GLOB_APPEND;
+	}
+	for (i = 0; i < gl.gl_pathc; i++) {
+		struct fastindex_entry *e;
+		struct stat st;
+
+		if (stat(gl.gl_pathv[i], &st))
+			continue;
+
+		if ((st.st_mode & S_IFMT) != S_IFREG)
+			continue;
+
+		e = find_entry(f, gl.gl_pathv[i]);
+		if (!e) {
+			e = new_entry(f, gl.gl_pathv[i]);
+			list_add_tail(&e->list, &f->entries);
+		}
+
+		e->checked = f->checked;
+		if ((e->timestamp < st.st_mtime)) {
+			load_index(f, e);
+			e->timestamp = st.st_mtime;
+		}
+	}
+	globfree(&gl);
+	list_for_each_safe(p, tmp, &f->entries) {
+		struct fastindex_entry *e = container_of(p, struct fastindex_entry, list);
+		if (e->checked < f->checked) {
+			lua_pushnil(f->L);
+			lua_setfield(f->L, -2, e->name);
+			free_entry(e);
+		}
+	}
+	lua_pop(L, 1);
+
+	return 0;
+}
+
+static int
+fastindex_free(lua_State *L)
+{
+	struct fastindex *f;
+	struct list_head *p, *tmp;
+
+	f = lua_touserdata(L, -1);
+	list_for_each_safe(p, tmp, &f->patterns) {
+		struct fastindex_pattern *pt;
+		pt = container_of(p, struct fastindex_pattern, list);
+		list_del(p);
+		free(pt);
+	}
+	list_for_each_safe(p, tmp, &f->entries) {
+		struct fastindex_entry *e;
+		e = container_of(p, struct fastindex_entry, list);
+		free_entry(e);
+	}
+	return 0;
+}
+
+static int
+fastindex_add(lua_State *L)
+{
+	struct fastindex_pattern *pt;
+	struct fastindex *f;
+	const char *str;
+
+	f = to_fastindex(L);
+	str = luaL_checkstring(L, 1);
+	if (!str)
+		luaL_error(L, "Invalid argument");
+
+	pt = malloc(sizeof(struct fastindex_pattern) + strlen(str) + 1);
+	if (!pt)
+		luaL_error(L, "Out of memory");
+
+	INIT_LIST_HEAD(&pt->list);
+	strcpy(pt->pattern, str);
+	list_add(&pt->list, &f->patterns);
+
+	return 0;
+}
+
+static const luaL_Reg fastindex_m[] = {
+	{ "add", fastindex_add },
+	{ "scan", fastindex_scan },
+	{ NULL, NULL }
+};
+
+static int
+fastindex_new(lua_State *L)
+{
+	struct fastindex *f;
+	const char *func;
+
+	func = luaL_checkstring(L, 1);
+
+	f = lua_newuserdata(L, sizeof(struct fastindex));
+	lua_createtable(L, 0, 2);
+	lua_pushvalue(L, -1);
+	lua_setfield(L, -2, "__index");
+	lua_pushcfunction(L, fastindex_free);
+	lua_setfield(L, -2, "__gc");
+	lua_pushvalue(L, -1);
+	lua_setmetatable(L, -3);
+	lua_pushvalue(L, -2);
+	lua_setfield(L, -2, "__data");
+	lua_createtable(L, 0, 1);
+	lua_setfield(L, -2, "indexes");
+	lua_pushvalue(L, -2);
+	luaI_openlib(L, NULL, fastindex_m, 1);
+
+	memset(f, 0, sizeof(struct fastindex));
+	f->L = L;
+	f->buflen = DEFAULT_BUFLEN;
+	INIT_LIST_HEAD(&f->entries);
+	INIT_LIST_HEAD(&f->patterns);
+
+	f->func = strdup(func);
+	if (!f->func) {
+		if (f->func)
+			free(f->func);
+		luaL_error(L, "Out of memory\n");
+	}
+
+	return 1;
+}
+
+static const luaL_Reg fastindex[] = {
+	{ "new", fastindex_new },
+	{ NULL, NULL },
+};
+
+int
+luaopen_fastindex(lua_State *L)
+{
+	luaL_register(L, MODNAME, fastindex);
+	return 0;
+}