commit 801f43f09a3c95a2ec4011a0dc8558ba25a0cc72
parent 719c01359f797e3933a7a69b541d7e57e149d061
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 21 Jun 2011 10:43:24 -0300
change in the representation of file handles
Diffstat:
| M | liolib.c | | | 267 | ++++++++++++++++++++++++++++++++++++++----------------------------------------- |
1 file changed, 128 insertions(+), 139 deletions(-)
diff --git a/liolib.c b/liolib.c
@@ -1,5 +1,5 @@
/*
-** $Id: liolib.c,v 2.98 2011/02/21 19:12:54 roberto Exp roberto $
+** $Id: liolib.c,v 2.99 2011/03/03 16:34:46 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@@ -19,8 +19,6 @@
#include "lualib.h"
-#define MAX_SIZE_T (~(size_t)0)
-
/*
** lua_popen spawns a new process connected to the current one through
@@ -51,11 +49,15 @@
#endif /* } */
-#define IO_INPUT 1
-#define IO_OUTPUT 2
+#define IO_PREFIX "lua_io_"
+#define IO_INPUT (IO_PREFIX "input")
+#define IO_OUTPUT (IO_PREFIX "output")
-static const char *const fnames[] = {"input", "output"};
+typedef struct LStream {
+ FILE *f; /* stream */
+ lua_CFunction closef; /* to close stream (NULL for closed streams) */
+} LStream;
static void fileerror (lua_State *L, int arg, const char *filename) {
@@ -64,16 +66,18 @@ static void fileerror (lua_State *L, int arg, const char *filename) {
}
-#define tofilep(L) ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
+#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))
+
+#define isclosed(p) ((p)->closef == NULL)
static int io_type (lua_State *L) {
- void *ud;
+ LStream *p;
luaL_checkany(L, 1);
- ud = luaL_testudata(L, 1, LUA_FILEHANDLE);
- if (ud == NULL)
+ p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
+ if (p == NULL)
lua_pushnil(L); /* not a file */
- else if (*((FILE **)ud) == NULL)
+ else if (isclosed(p))
lua_pushliteral(L, "closed file");
else
lua_pushliteral(L, "file");
@@ -81,11 +85,22 @@ static int io_type (lua_State *L) {
}
+static int f_tostring (lua_State *L) {
+ LStream *p = tolstream(L);
+ if (isclosed(p))
+ lua_pushliteral(L, "file (closed)");
+ else
+ lua_pushfstring(L, "file (%p)", p->f);
+ return 1;
+}
+
+
static FILE *tofile (lua_State *L) {
- FILE **f = tofilep(L);
- if (*f == NULL)
+ LStream *p = tolstream(L);
+ if (isclosed(p))
luaL_error(L, "attempt to use a closed file");
- return *f;
+ lua_assert(p->f);
+ return p->f;
}
@@ -94,40 +109,35 @@ static FILE *tofile (lua_State *L) {
** before opening the actual file; so, if there is a memory error, the
** file is not left opened.
*/
-static FILE **newprefile (lua_State *L) {
- FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
- *pf = NULL; /* file handle is currently `closed' */
+static LStream *newprefile (lua_State *L) {
+ LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
+ p->closef = NULL; /* mark file handle as 'closed' */
luaL_setmetatable(L, LUA_FILEHANDLE);
- return pf;
+ return p;
}
-static FILE **newfile (lua_State *L) {
- FILE **pf = newprefile(L);
- lua_pushvalue(L, lua_upvalueindex(1)); /* set upvalue... */
- lua_setuservalue(L, -2); /* ... as environment for new file */
- return pf;
+static int aux_close (lua_State *L) {
+ LStream *p = tolstream(L);
+ lua_CFunction cf = p->closef;
+ p->closef = NULL; /* mark stream as closed */
+ return (*cf)(L); /* close it */
}
-/*
-** function to (not) close the standard files stdin, stdout, and stderr
-*/
-static int io_noclose (lua_State *L) {
- lua_pushnil(L);
- lua_pushliteral(L, "cannot close standard file");
- return 2;
+static int io_close (lua_State *L) {
+ if (lua_isnone(L, 1)) /* no argument? */
+ lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */
+ tofile(L); /* make sure argument is an open stream */
+ return aux_close(L);
}
-/*
-** function to close 'popen' files
-*/
-static int io_pclose (lua_State *L) {
- FILE **p = tofilep(L);
- int stat = lua_pclose(L, *p);
- *p = NULL; /* mark stream as closed (for GC) */
- return luaL_execresult(L, stat);
+static int f_gc (lua_State *L) {
+ LStream *p = tolstream(L);
+ if (!isclosed(p) && p->f != NULL)
+ aux_close(L); /* ignore closed and incompletely open files */
+ return 0;
}
@@ -135,111 +145,90 @@ static int io_pclose (lua_State *L) {
** function to close regular files
*/
static int io_fclose (lua_State *L) {
- FILE **p = tofilep(L);
- int ok = (fclose(*p) == 0);
- *p = NULL; /* mark stream as closed (for GC) */
- return luaL_fileresult(L, ok, NULL);
+ LStream *p = tolstream(L);
+ int res = fclose(p->f);
+ return luaL_fileresult(L, (res == 0), NULL);
}
-static int aux_close (lua_State *L) {
- lua_getuservalue(L, 1);
- lua_getfield(L, -1, "__close");
- return (lua_tocfunction(L, -1))(L);
-}
-
-
-static int io_close (lua_State *L) {
- if (lua_isnone(L, 1))
- lua_rawgeti(L, lua_upvalueindex(1), IO_OUTPUT);
- tofile(L); /* make sure argument is a file */
- return aux_close(L);
-}
-
-
-static int io_gc (lua_State *L) {
- FILE *f = *tofilep(L);
- if (f != NULL) /* ignore closed files */
- aux_close(L);
- return 0;
-}
-
-
-static int io_tostring (lua_State *L) {
- FILE *f = *tofilep(L);
- if (f == NULL)
- lua_pushliteral(L, "file (closed)");
- else
- lua_pushfstring(L, "file (%p)", f);
- return 1;
+static LStream *newfile (lua_State *L) {
+ LStream *p = newprefile(L);
+ p->f = NULL;
+ p->closef = &io_fclose;
+ return p;
}
static int io_open (lua_State *L) {
const char *filename = luaL_checkstring(L, 1);
const char *mode = luaL_optstring(L, 2, "r");
- FILE **pf;
+ LStream *p = newfile(L);
int i = 0;
/* check whether 'mode' matches '[rwa]%+?b?' */
if (!(mode[i] != '\0' && strchr("rwa", mode[i++]) != NULL &&
(mode[i] != '+' || ++i) && /* skip if char is '+' */
(mode[i] != 'b' || ++i) && /* skip if char is 'b' */
(mode[i] == '\0')))
- luaL_error(L, "invalid mode " LUA_QL("%s")
- " (should match " LUA_QL("[rwa]%%+?b?") ")", mode);
- pf = newfile(L);
- *pf = fopen(filename, mode);
- return (*pf == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+ return luaL_error(L, "invalid mode " LUA_QL("%s")
+ " (should match " LUA_QL("[rwa]%%+?b?") ")", mode);
+ p->f = fopen(filename, mode);
+ return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
}
/*
-** this function has a separated environment, which defines the
-** correct __close for 'popen' files
+** function to close 'popen' files
*/
+static int io_pclose (lua_State *L) {
+ LStream *p = tolstream(L);
+ return luaL_execresult(L, lua_pclose(L, p->f));
+}
+
+
static int io_popen (lua_State *L) {
const char *filename = luaL_checkstring(L, 1);
const char *mode = luaL_optstring(L, 2, "r");
- FILE **pf = newfile(L);
- *pf = lua_popen(L, filename, mode);
- return (*pf == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+ LStream *p = newprefile(L);
+ p->f = lua_popen(L, filename, mode);
+ p->closef = &io_pclose;
+ return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
}
static int io_tmpfile (lua_State *L) {
- FILE **pf = newfile(L);
- *pf = tmpfile();
- return (*pf == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
+ LStream *p = newfile(L);
+ p->f = tmpfile();
+ return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
}
-static FILE *getiofile (lua_State *L, int findex) {
- FILE *f;
- lua_rawgeti(L, lua_upvalueindex(1), findex);
- f = *(FILE **)lua_touserdata(L, -1);
- if (f == NULL)
- luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
- return f;
+static FILE *getiofile (lua_State *L, const char *findex) {
+ LStream *p;
+ lua_getfield(L, LUA_REGISTRYINDEX, findex);
+ p = (LStream *)lua_touserdata(L, -1);
+ if (isclosed(p))
+ luaL_error(L, "standard %s file is closed", findex + strlen(IO_PREFIX));
+ return p->f;
}
-static int g_iofile (lua_State *L, int f, const char *mode) {
+static int g_iofile (lua_State *L, const char *f, const char *mode) {
if (!lua_isnoneornil(L, 1)) {
const char *filename = lua_tostring(L, 1);
if (filename) {
- FILE **pf = newfile(L);
- *pf = fopen(filename, mode);
- if (*pf == NULL)
+ LStream *p = newfile(L);
+ p->f = fopen(filename, mode);
+ if (p->f == NULL)
fileerror(L, 1, filename);
}
else {
tofile(L); /* check that it's a valid file handle */
lua_pushvalue(L, 1);
}
- lua_rawseti(L, lua_upvalueindex(1), f);
+ lua_setfield(L, LUA_REGISTRYINDEX, f);
}
/* return current value */
- lua_rawgeti(L, lua_upvalueindex(1), f);
+ lua_getfield(L, LUA_REGISTRYINDEX, f);
return 1;
}
@@ -281,16 +270,16 @@ static int io_lines (lua_State *L) {
int toclose;
if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */
if (lua_isnil(L, 1)) { /* no file name? */
- lua_rawgeti(L, lua_upvalueindex(1), IO_INPUT); /* get default input */
+ lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */
lua_replace(L, 1); /* put it at index 1 */
tofile(L); /* check that it's a valid file handle */
toclose = 0; /* do not close it after iteration */
}
else { /* open a new file */
const char *filename = luaL_checkstring(L, 1);
- FILE **pf = newfile(L);
- *pf = fopen(filename, "r");
- if (*pf == NULL)
+ LStream *p = newfile(L);
+ p->f = fopen(filename, "r");
+ if (p->f == NULL)
fileerror(L, 1, filename);
lua_replace(L, 1); /* put file at index 1 */
toclose = 1; /* close it after iteration */
@@ -350,6 +339,8 @@ static int read_line (lua_State *L, FILE *f, int chop) {
}
+#define MAX_SIZE_T (~(size_t)0)
+
static void read_all (lua_State *L, FILE *f) {
size_t rlen = LUAL_BUFFERSIZE; /* how much to read in each cycle */
luaL_Buffer b;
@@ -440,15 +431,15 @@ static int f_read (lua_State *L) {
static int io_readline (lua_State *L) {
- FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
+ LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
int i;
int n = (int)lua_tointeger(L, lua_upvalueindex(2));
- if (f == NULL) /* file is already closed? */
- luaL_error(L, "file is already closed");
+ if (isclosed(p)) /* file is already closed? */
+ return luaL_error(L, "file is already closed");
lua_settop(L , 1);
for (i = 1; i <= n; i++) /* push arguments to 'g_read' */
lua_pushvalue(L, lua_upvalueindex(3 + i));
- n = g_read(L, f, 2); /* 'n' is number of results */
+ n = g_read(L, p->f, 2); /* 'n' is number of results */
lua_assert(n > 0); /* should return at least a nil */
if (!lua_isnil(L, -n)) /* read at least one value? */
return n; /* return them */
@@ -494,7 +485,7 @@ static int io_write (lua_State *L) {
static int f_write (lua_State *L) {
- FILE * f = tofile(L);
+ FILE *f = tofile(L);
lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */
return g_write(L, f, 2);
}
@@ -538,6 +529,9 @@ static int f_flush (lua_State *L) {
}
+/*
+** functions for 'io' library
+*/
static const luaL_Reg iolib[] = {
{"close", io_close},
{"flush", io_flush},
@@ -554,6 +548,9 @@ static const luaL_Reg iolib[] = {
};
+/*
+** methods for file handles
+*/
static const luaL_Reg flib[] = {
{"close", io_close},
{"flush", f_flush},
@@ -562,8 +559,8 @@ static const luaL_Reg flib[] = {
{"seek", f_seek},
{"setvbuf", f_setvbuf},
{"write", f_write},
- {"__gc", io_gc},
- {"__tostring", io_tostring},
+ {"__gc", f_gc},
+ {"__tostring", f_tostring},
{NULL, NULL}
};
@@ -577,46 +574,38 @@ static void createmeta (lua_State *L) {
}
-static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
- *newprefile(L) = f;
- if (k > 0) {
- lua_pushvalue(L, -1); /* copy new file */
- lua_rawseti(L, 1, k); /* add it to common upvalue */
- }
- lua_pushvalue(L, 3); /* get environment for default files */
- lua_setuservalue(L, -2); /* set it as environment for file */
- lua_setfield(L, 2, fname); /* add file to module */
+/*
+** function to (not) close the standard files stdin, stdout, and stderr
+*/
+static int io_noclose (lua_State *L) {
+ LStream *p = tolstream(L);
+ p->closef = &io_noclose; /* keep file opened */
+ lua_pushnil(L);
+ lua_pushliteral(L, "cannot close standard file");
+ return 2;
}
-/*
-** pushes a new table with {__close = cls}
-*/
-static void newenv (lua_State *L, lua_CFunction cls) {
- lua_createtable(L, 0, 1);
- lua_pushcfunction(L, cls);
- lua_setfield(L, -2, "__close");
+static void createstdfile (lua_State *L, FILE *f, const char *k,
+ const char *fname) {
+ LStream *p = newprefile(L);
+ p->f = f;
+ p->closef = &io_noclose;
+ if (k != NULL) {
+ lua_pushvalue(L, -1);
+ lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */
+ }
+ lua_setfield(L, -2, fname); /* add file to module */
}
LUAMOD_API int luaopen_io (lua_State *L) {
- lua_settop(L, 0);
+ luaL_newlib(L, iolib); /* new module */
createmeta(L);
- /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
- newenv(L, io_fclose); /* upvalue for all io functions at index 1 */
- luaL_newlibtable(L, iolib); /* new module at index 2 */
- lua_pushvalue(L, 1); /* copy of env to be consumed by 'setfuncs' */
- luaL_setfuncs(L, iolib, 1);
/* create (and set) default files */
- newenv(L, io_noclose); /* environment for default files at index 3 */
createstdfile(L, stdin, IO_INPUT, "stdin");
createstdfile(L, stdout, IO_OUTPUT, "stdout");
- createstdfile(L, stderr, 0, "stderr");
- lua_pop(L, 1); /* pop environment for default files */
- lua_getfield(L, 2, "popen");
- newenv(L, io_pclose); /* create environment for 'popen' streams */
- lua_setupvalue(L, -2, 1); /* set it as upvalue for 'popen' */
- lua_pop(L, 1); /* pop 'popen' */
+ createstdfile(L, stderr, NULL, "stderr");
return 1;
}
