Add read, write, and close wrapers

Stdio only works well with regular files. For pipes, the native syscalls
work much better.

Signed-off-by: Tobias Ulmer <tu@emlix.com>

diff --git a/generic/leio.c b/generic/leio.c
index d6d710148987c10c8683ccbd17b19f079ce5c2ae..8e45f78cfa617dc5a8010b1dda7c8be2d87a1ba3 100644 (file)
--- a/generic/leio.c
+++ b/generic/leio.c
@@ -87,6 +87,23 @@ eio_fclose(lua_State *lua)
        return 1;
 }
 
+static int
+eio_close(lua_State *L)
+{
+       int fd, rc;
+
+       fd = luaL_checkinteger(L, 1);
+       rc = close(fd);
+       if (rc < 0) {
+               lua_pushboolean(L, 0);
+               lua_pushstring(L, strerror(errno));
+               return 2;
+       }
+
+       lua_pushboolean(L, 1);
+       return 1;
+}
+
 static int
 eio_fdopen(lua_State *lua)
 {
@@ -145,6 +162,48 @@ eio_fwrite(lua_State *lua)
        return 1;
 }
 
+static int
+eio_write(lua_State *L)
+{
+       int fd;
+       const char *buf;
+       size_t sz;
+       ssize_t wsz;
+
+       fd = luaL_checkinteger(L, 1);
+       buf = lua_tolstring(L, 2, &sz);
+
+       wsz = write(fd, buf, sz);
+       if (wsz < 0) {
+               lua_pushboolean(L, 0);
+               lua_pushstring(L, strerror(errno));
+               lua_pushinteger(L, errno);
+               return 3;
+       }
+
+       lua_pushinteger(L, wsz);
+       return 1;
+}
+
+static char *
+get_read_buf(size_t sz)
+{
+       static char *buf;
+       static size_t bufsz;
+
+       if (sz > bufsz) {
+               free(buf);
+               bufsz = 0;
+               buf = malloc(sz);
+               if (!buf)
+                       return NULL;
+
+               bufsz = sz;
+       }
+
+       return buf;
+}
+
 static int
 eio_fread(lua_State *lua)
 {
@@ -161,7 +220,7 @@ eio_fread(lua_State *lua)
                return 2;
        }
 
-       buf = malloc(sz);
+       buf = get_read_buf(sz);
        if (buf == NULL) {
                lua_pushboolean(lua, 0);
                lua_pushstring(lua, strerror(errno));
@@ -171,7 +230,6 @@ eio_fread(lua_State *lua)
        ret = fread(buf, 1, sz, f);
        if (ret != sz) {
                if (ferror(f)) {
-                       free(buf);
                        lua_pushboolean(lua, 0);
                        lua_pushstring(lua, strerror(errno));
                        return 2;
@@ -180,14 +238,43 @@ eio_fread(lua_State *lua)
                if (ret <= 0 && feof(f)) {
                        /* ret <= 0: do not discard data on short reads,
                         * only signal EOF when all data is returned. */
-                       free(buf);
                        lua_pushstring(lua, "");
                        return 1;
                }
        }
 
        lua_pushlstring(lua, buf, ret);
-       free(buf);
+       return 1;
+}
+
+static int
+eio_read(lua_State *L)
+{
+       int fd;
+       size_t sz;
+       ssize_t rsz;
+       char *buf;
+
+
+       fd = luaL_checkinteger(L, 1);
+       sz = luaL_checkinteger(L, 2);
+
+       buf = get_read_buf(sz);
+       if (buf == NULL) {
+               lua_pushboolean(L, 0);
+               lua_pushstring(L, strerror(errno));
+               return 2;
+       }
+
+       rsz = read(fd, buf, sz);
+       if (rsz < 0) {
+               lua_pushboolean(L, 0);
+               lua_pushstring(L, strerror(errno));
+               lua_pushinteger(L, errno);
+               return 3;
+       }
+
+       lua_pushlstring(L, buf, rsz);
        return 1;
 }
 
@@ -380,6 +467,7 @@ eio_cloexec(lua_State *lua)
 
 static luaL_Reg lib[] = {
   { "cloexec", eio_cloexec },
+  { "close", eio_close },
   { "dup2", eio_dup2 },
   { "fclose", eio_fclose },
   { "fdopen", eio_fdopen },
@@ -390,8 +478,10 @@ static luaL_Reg lib[] = {
   { "fread", eio_fread },
   { "fwrite", eio_fwrite },
   { "pipe", eio_pipe },
+  { "read", eio_read },
   { "setlinebuf", eio_setlinebuf },
   { "setunbuffered", eio_setunbuffered },
+  { "write", eio_write },
   { NULL, NULL }
 };