mirror of https://github.com/lua/lua
Avoid the creation of too many strings in 'package'
Both when setting a path and searching for a file ('searchpath'), this commit reduces the number of intermediate strings created in Lua. (For setting a path the change is not relevant, because this is done only twice when loading the module. Anyway, it is a nice example of how to use auxlib buffers to manipulate strings in the C API.)
This commit is contained in:
parent
b36e26f51b
commit
b14609032c
2
lgc.h
2
lgc.h
|
@ -127,7 +127,7 @@
|
|||
|
||||
/*
|
||||
** some gc parameters are stored divided by 4 to allow a maximum value
|
||||
** larger than 1000 in a 'lu_byte'.
|
||||
** up to 1023 in a 'lu_byte'.
|
||||
*/
|
||||
#define getgcparam(p) ((p) * 4)
|
||||
#define setgcparam(p,v) ((p) = (v) / 4)
|
||||
|
|
|
@ -39,7 +39,7 @@ typedef signed char ls_byte;
|
|||
/* maximum value for size_t */
|
||||
#define MAX_SIZET ((size_t)(~(size_t)0))
|
||||
|
||||
/* maximum size visible for Lua (must be representable in a lua_Integer */
|
||||
/* maximum size visible for Lua (must be representable in a lua_Integer) */
|
||||
#define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \
|
||||
: (size_t)(LUA_MAXINTEGER))
|
||||
|
||||
|
|
89
loadlib.c
89
loadlib.c
|
@ -290,22 +290,33 @@ static int noenv (lua_State *L) {
|
|||
static void setpath (lua_State *L, const char *fieldname,
|
||||
const char *envname,
|
||||
const char *dft) {
|
||||
const char *dftmark;
|
||||
const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX);
|
||||
const char *path = getenv(nver); /* use versioned name */
|
||||
if (path == NULL) /* no environment variable? */
|
||||
const char *path = getenv(nver); /* try versioned name */
|
||||
if (path == NULL) /* no versioned environment variable? */
|
||||
path = getenv(envname); /* try unversioned name */
|
||||
if (path == NULL || noenv(L)) /* no environment variable? */
|
||||
lua_pushstring(L, dft); /* use default */
|
||||
else {
|
||||
/* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
|
||||
path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
|
||||
LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
|
||||
luaL_gsub(L, path, AUXMARK, dft);
|
||||
lua_remove(L, -2); /* remove result from 1st 'gsub' */
|
||||
else if ((dftmark = strstr(path, LUA_PATH_SEP LUA_PATH_SEP)) == NULL)
|
||||
lua_pushstring(L, path); /* nothing to change */
|
||||
else { /* path contains a ";;": insert default path in its place */
|
||||
size_t len = strlen(path);
|
||||
luaL_Buffer b;
|
||||
luaL_buffinit(L, &b);
|
||||
if (path < dftmark) { /* is there a prefix before ';;'? */
|
||||
luaL_addlstring(&b, path, dftmark - path); /* add it */
|
||||
luaL_addchar(&b, *LUA_PATH_SEP);
|
||||
}
|
||||
luaL_addstring(&b, dft); /* add default */
|
||||
if (dftmark < path + len - 2) { /* is there a sufix after ';;'? */
|
||||
luaL_addchar(&b, *LUA_PATH_SEP);
|
||||
luaL_addlstring(&b, dftmark + 2, (path + len - 2) - dftmark);
|
||||
}
|
||||
luaL_pushresult(&b);
|
||||
}
|
||||
setprogdir(L);
|
||||
lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */
|
||||
lua_pop(L, 1); /* pop versioned variable name */
|
||||
lua_pop(L, 1); /* pop versioned variable name ('nver') */
|
||||
}
|
||||
|
||||
/* }================================================================== */
|
||||
|
@ -421,17 +432,26 @@ static int readable (const char *filename) {
|
|||
}
|
||||
|
||||
|
||||
static const char *pushnextfilename (lua_State *L, const char *path) {
|
||||
const char *l;
|
||||
if (*path == *LUA_PATH_SEP)
|
||||
path++; /* skip separator */
|
||||
if (*path == '\0')
|
||||
/*
|
||||
** Get the next name in '*path' = 'name1;name2;name3;...', changing
|
||||
** the ending ';' to '\0' to create a zero-terminated string. Return
|
||||
** NULL when list ends.
|
||||
*/
|
||||
static const char *getnextfilename (char **path, char *end) {
|
||||
char *sep;
|
||||
char *name = *path;
|
||||
if (name == end)
|
||||
return NULL; /* no more names */
|
||||
l = strchr(path, *LUA_PATH_SEP); /* find next separator */
|
||||
if (l == NULL) /* no more separators? */
|
||||
l = path + strlen(path); /* go until the end */
|
||||
lua_pushlstring(L, path, l - path); /* file name */
|
||||
return l; /* rest of the path */
|
||||
else if (*name == '\0') { /* from previous iteration? */
|
||||
*name = *LUA_PATH_SEP; /* restore separator */
|
||||
name++; /* skip it */
|
||||
}
|
||||
sep = strchr(name, *LUA_PATH_SEP); /* find next separator */
|
||||
if (sep == NULL) /* separator not found? */
|
||||
sep = end; /* name goes until the end */
|
||||
*sep = '\0'; /* finish file name */
|
||||
*path = sep; /* will start next search from here */
|
||||
return name;
|
||||
}
|
||||
|
||||
|
||||
|
@ -442,12 +462,12 @@ static const char *pushnextfilename (lua_State *L, const char *path) {
|
|||
** no file 'blublu.so'
|
||||
*/
|
||||
static void pusherrornotfound (lua_State *L, const char *path) {
|
||||
if (*path == *LUA_PATH_SEP)
|
||||
path++; /* skip separator */
|
||||
lua_pushstring(L, "\n\tno file '");
|
||||
luaL_gsub(L, path, LUA_PATH_SEP, "'\n\tno file '");
|
||||
lua_pushstring(L, "'");
|
||||
lua_concat(L, 3);
|
||||
luaL_Buffer b;
|
||||
luaL_buffinit(L, &b);
|
||||
luaL_addstring(&b, "\n\tno file '");
|
||||
luaL_addgsub(&b, path, LUA_PATH_SEP, "'\n\tno file '");
|
||||
luaL_addstring(&b, "'");
|
||||
luaL_pushresult(&b);
|
||||
}
|
||||
|
||||
|
||||
|
@ -455,17 +475,24 @@ static const char *searchpath (lua_State *L, const char *name,
|
|||
const char *path,
|
||||
const char *sep,
|
||||
const char *dirsep) {
|
||||
luaL_Buffer buff;
|
||||
char *pathname; /* path with name inserted */
|
||||
char *endpathname; /* its end */
|
||||
const char *filename;
|
||||
/* separator is non-empty and appears in 'name'? */
|
||||
if (*sep != '\0' && strchr(name, *sep) != NULL)
|
||||
name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
|
||||
/* replace marks ('?') in 'path' by the file name */
|
||||
path = luaL_gsub(L, path, LUA_PATH_MARK, name);
|
||||
while ((path = pushnextfilename(L, path)) != NULL) {
|
||||
const char *filename = lua_tostring(L, -1);
|
||||
luaL_buffinit(L, &buff);
|
||||
/* add path to the buffer, replacing marks ('?') with the file name */
|
||||
luaL_addgsub(&buff, path, LUA_PATH_MARK, name);
|
||||
luaL_addchar(&buff, '\0');
|
||||
pathname = luaL_buffaddr(&buff); /* writable list of file names */
|
||||
endpathname = pathname + luaL_bufflen(&buff) - 1;
|
||||
while ((filename = getnextfilename(&pathname, endpathname)) != NULL) {
|
||||
if (readable(filename)) /* does file exist and is readable? */
|
||||
return filename; /* return that file name */
|
||||
lua_pop(L, 1); /* else remove file name */
|
||||
return lua_pushstring(L, filename); /* save and return name */
|
||||
}
|
||||
luaL_pushresult(&buff); /* push path to create error message */
|
||||
pusherrornotfound(L, lua_tostring(L, -1)); /* create error message */
|
||||
return NULL; /* not found */
|
||||
}
|
||||
|
|
|
@ -142,12 +142,18 @@ do
|
|||
prepfile("print(package.path, package.cpath)")
|
||||
RUN('env LUA_INIT="error(10)" LUA_PATH=xxx LUA_CPATH=xxx lua -E %s > %s',
|
||||
prog, out)
|
||||
local output = getoutput()
|
||||
defaultpath = string.match(output, "^(.-)\t")
|
||||
defaultCpath = string.match(output, "\t(.-)$")
|
||||
|
||||
-- running with an empty environment
|
||||
RUN('env -i lua %s > %s', prog, out)
|
||||
local out = getoutput()
|
||||
defaultpath = string.match(out, "^(.-)\t")
|
||||
defaultCpath = string.match(out, "\t(.-)$")
|
||||
assert(defaultpath == string.match(output, "^(.-)\t"))
|
||||
assert(defaultCpath == string.match(output, "\t(.-)$"))
|
||||
end
|
||||
|
||||
-- paths did not changed
|
||||
-- paths did not change
|
||||
assert(not string.find(defaultpath, "xxx") and
|
||||
string.find(defaultpath, "lua") and
|
||||
not string.find(defaultCpath, "xxx") and
|
||||
|
@ -160,15 +166,20 @@ local function convert (p)
|
|||
RUN('env LUA_PATH="%s" lua %s > %s', p, prog, out)
|
||||
local expected = getoutput()
|
||||
expected = string.sub(expected, 1, -2) -- cut final end of line
|
||||
assert(string.gsub(p, ";;", ";"..defaultpath..";") == expected)
|
||||
if string.find(p, ";;") then
|
||||
p = string.gsub(p, ";;", ";"..defaultpath..";")
|
||||
p = string.gsub(p, "^;", "") -- remove ';' at the beginning
|
||||
p = string.gsub(p, ";$", "") -- remove ';' at the end
|
||||
end
|
||||
assert(p == expected)
|
||||
end
|
||||
|
||||
convert(";")
|
||||
convert(";;")
|
||||
convert(";;;")
|
||||
convert(";;;;")
|
||||
convert(";;;;;")
|
||||
convert(";;a;;;bc")
|
||||
convert("a;;b")
|
||||
convert(";;b")
|
||||
convert("a;;")
|
||||
convert("a;b;;c")
|
||||
|
||||
|
||||
-- test -l over multiple libraries
|
||||
|
|
Loading…
Reference in New Issue