Lua:

 * add IO lib (adapted to Rockbox)
 * remove old IO wrappers
 * rework helloworld.lua to work with the IO lib
 * do some stuff in helloworld.lua better (part of FS#10379, by James Callahan)


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21541 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 479 insertions, 0 deletions

diff --git a/apps/plugins/lua/liolib.c b/apps/plugins/lua/liolib.c
new file mode 100644
index 0000000..2ea52b8
--- /dev/null
+++ b/apps/plugins/lua/liolib.c
@@ -0,0 +1,479 @@
+/*
+** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 roberto Exp $
+** Standard I/O (and system) library
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define liolib_c
+#define LUA_LIB
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+#include "rocklibc.h"
+
+
+
+#define IO_INPUT    1
+#define IO_OUTPUT   2
+
+
+static const char *const fnames[] = {"input", "output"};
+
+
+static int pushresult (lua_State *L, int i, const char *filename) {
+  int en = errno;
+  if (i) {
+    lua_pushboolean(L, 1);
+    return 1;
+  }
+  else {
+    lua_pushnil(L);
+    if (filename)
+      lua_pushfstring(L, "%s: %s", filename, strerror(en));
+    else
+      lua_pushfstring(L, "%s", strerror(en));
+    lua_pushinteger(L, 0);
+    return 3;
+  }
+}
+
+
+static void fileerror (lua_State *L, int arg, const char *filename) {
+  lua_pushfstring(L, "%s: %s", filename, strerror(errno));
+  luaL_argerror(L, arg, lua_tostring(L, -1));
+}
+
+
+static int io_type (lua_State *L) {
+  void *ud;
+  luaL_checkany(L, 1);
+  ud = lua_touserdata(L, 1);
+  lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
+  if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
+    lua_pushnil(L);  /* not a file */
+  else if (*((int *)ud) < 0)
+    lua_pushliteral(L, "closed file");
+  else
+    lua_pushliteral(L, "file");
+  return 1;
+}
+
+
+static int* tofile (lua_State *L) {
+  int *f = (int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
+  if (*f < 0)
+    luaL_error(L, "attempt to use a closed file");
+  return f;
+}
+
+
+
+/*
+** When creating file handles, always creates a `closed' file handle
+** before opening the actual file; so, if there is a memory error, the
+** file is not left opened.
+*/
+static int* newfile (lua_State *L) {
+  int *pf = (int *)lua_newuserdata(L, sizeof(int));
+  *pf = -1;  /* file handle is currently `closed' */
+  luaL_getmetatable(L, LUA_FILEHANDLE);
+  lua_setmetatable(L, -2);
+  return pf;
+}
+
+
+/*
+** function to close regular files
+*/
+static int io_fclose (lua_State *L) {
+  int *p = tofile(L);
+  int ok = (rb->close(*p) == 0);
+  *p = -1;
+  return pushresult(L, ok, NULL);
+}
+
+
+static inline int aux_close (lua_State *L) {
+  return io_fclose(L);
+}
+
+
+static int io_close (lua_State *L) {
+  if (lua_isnone(L, 1))
+    lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
+  tofile(L);  /* make sure argument is a file */
+  return aux_close(L);
+}
+
+
+static int io_gc (lua_State *L) {
+  int f = *(int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
+  /* ignore closed files */
+  if (f >= 0)
+    aux_close(L);
+  return 0;
+}
+
+
+static int io_tostring (lua_State *L) {
+  int f = *(int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
+  if (f < 0)
+    lua_pushliteral(L, "file (closed)");
+  else
+    lua_pushfstring(L, "file (%d)", f);
+  return 1;
+}
+
+
+static int io_open (lua_State *L) {
+  const char *filename = luaL_checkstring(L, 1);
+  const char *mode = luaL_optstring(L, 2, "r");
+  int *pf = newfile(L);
+  int flags = 0;
+  if(*(mode+1) == '+') {
+    flags = O_RDWR;
+    switch(*mode) {
+        case 'w':
+            flags |= O_TRUNC; break;
+        case 'a':
+            flags |= O_APPEND; break;
+    }
+  }
+  else {
+    switch(*mode) {
+        case 'r':
+            flags = O_RDONLY; break;
+        case 'w':
+            flags = O_WRONLY; break;
+        case 'a':
+            flags = O_WRONLY | O_APPEND; break;
+    }
+  }
+  if(!rb->file_exists(filename))
+      flags |= O_CREAT;
+  *pf = rb->open(filename, flags);
+  return (*pf < 0) ? pushresult(L, 0, filename) : 1;
+}
+
+
+static int* getiofile (lua_State *L, int findex) {
+  int *f;
+  lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
+  f = (int *)lua_touserdata(L, -1);
+  if (f == NULL || *f < 0)
+    luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
+  return f;
+}
+
+
+static int g_iofile (lua_State *L, int f, int flags) {
+  if (!lua_isnoneornil(L, 1)) {
+    const char *filename = lua_tostring(L, 1);
+    if (filename) {
+      int *pf = newfile(L);
+      *pf = rb->open(filename, flags);
+      if (*pf < 0)
+        fileerror(L, 1, filename);
+    }
+    else {
+      tofile(L);  /* check that it's a valid file handle */
+      lua_pushvalue(L, 1);
+    }
+    lua_rawseti(L, LUA_ENVIRONINDEX, f);
+  }
+  /* return current value */
+  lua_rawgeti(L, LUA_ENVIRONINDEX, f);
+  return 1;
+}
+
+
+static int io_input (lua_State *L) {
+  return g_iofile(L, IO_INPUT, O_RDONLY);
+}
+
+
+static int io_output (lua_State *L) {
+  return g_iofile(L, IO_OUTPUT, O_WRONLY);
+}
+
+
+static int io_readline (lua_State *L);
+
+
+static void aux_lines (lua_State *L, int idx, int toclose) {
+  lua_pushvalue(L, idx);
+  lua_pushboolean(L, toclose);  /* close/not close file when finished */
+  lua_pushcclosure(L, io_readline, 2);
+}
+
+
+static int f_lines (lua_State *L) {
+  tofile(L);  /* check that it's a valid file handle */
+  aux_lines(L, 1, 0);
+  return 1;
+}
+
+
+static int io_lines (lua_State *L) {
+  if (lua_isnoneornil(L, 1)) {  /* no arguments? */
+    /* will iterate over default input */
+    lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
+    return f_lines(L);
+  }
+  else {
+    const char *filename = luaL_checkstring(L, 1);
+    int *pf = newfile(L);
+    *pf = rb->open(filename, O_RDONLY);
+    if (*pf < 0)
+      fileerror(L, 1, filename);
+    aux_lines(L, lua_gettop(L), 1);
+    return 1;
+  }
+}
+
+
+/*
+** {======================================================
+** READ
+** =======================================================
+*/
+
+
+static int read_number (lua_State *L, int *f) {
+  char buf[10]; /* Maximum uint32 value is 10 chars long */
+  lua_Number d;
+  int i = 0;
+  /* Rather hackish, but we don't have fscanf.
+     Was: fscanf(f, LUA_NUMBER_SCAN, &d); */
+  memset(buf, 0, 10);
+  rb->read(*f, buf, 10);
+  while(isdigit(buf[i]) && i < 10)
+    i++;
+  if(i == 0) return 0;
+  else {
+    rb->lseek(*f, i-10, SEEK_CUR);
+    d = atoi(buf);
+    lua_pushnumber(L, d);
+    return 1;
+  }
+}
+
+
+static int test_eof (lua_State *L, int *f) {
+  ssize_t s = rb->lseek(*f, 0, SEEK_CUR);
+  lua_pushlstring(L, NULL, 0);
+  return s != rb->filesize(*f);
+}
+
+
+/* Rockbox already defines read_line() */
+static int _read_line (lua_State *L, int *f) {
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  for (;;) {
+    size_t l;
+    size_t r;
+    char *p = luaL_prepbuffer(&b);
+    r = rb->read_line(*f, p, LUAL_BUFFERSIZE);
+    l = strlen(p);
+    if (l == 0 || p[l-1] != '\n')
+      luaL_addsize(&b, l);
+    else {
+      luaL_addsize(&b, l - 1);  /* do not include `eol' */
+      luaL_pushresult(&b);  /* close buffer */
+      return 1;  /* read at least an `eol' */
+    }
+    if (r < LUAL_BUFFERSIZE) {  /* eof? */
+      luaL_pushresult(&b);  /* close buffer */
+      return (lua_objlen(L, -1) > 0);  /* check whether read something */
+    }
+  }
+}
+
+
+static int read_chars (lua_State *L, int *f, size_t n) {
+  size_t rlen;  /* how much to read */
+  size_t nr;  /* number of chars actually read */
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
+  do {
+    char *p = luaL_prepbuffer(&b);
+    if (rlen > n) rlen = n;  /* cannot read more than asked */
+    nr = rb->read(*f, p, rlen);
+    luaL_addsize(&b, nr);
+    n -= nr;  /* still have to read `n' chars */
+  } while (n > 0 && nr == rlen);  /* until end of count or eof */
+  luaL_pushresult(&b);  /* close buffer */
+  return (n == 0 || lua_objlen(L, -1) > 0);
+}
+
+
+static int g_read (lua_State *L, int *f, int first) {
+  int nargs = lua_gettop(L) - 1;
+  int success;
+  int n;
+  if (nargs == 0) {  /* no arguments? */
+    success = _read_line(L, f);
+    n = first+1;  /* to return 1 result */
+  }
+  else {  /* ensure stack space for all results and for auxlib's buffer */
+    luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
+    success = 1;
+    for (n = first; nargs-- && success; n++) {
+      if (lua_type(L, n) == LUA_TNUMBER) {
+        size_t l = (size_t)lua_tointeger(L, n);
+        success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
+      }
+      else {
+        const char *p = lua_tostring(L, n);
+        luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
+        switch (p[1]) {
+          case 'n':  /* number */
+            success = read_number(L, f);
+            break;
+          case 'l':  /* line */
+            success = _read_line(L, f);
+            break;
+          case 'a':  /* file */
+            read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
+            success = 1; /* always success */
+            break;
+          default:
+            return luaL_argerror(L, n, "invalid format");
+        }
+      }
+    }
+  }
+  if (!success) {
+    lua_pop(L, 1);  /* remove last result */
+    lua_pushnil(L);  /* push nil instead */
+  }
+  return n - first;
+}
+
+
+static int io_read (lua_State *L) {
+  return g_read(L, getiofile(L, IO_INPUT), 1);
+}
+
+
+static int f_read (lua_State *L) {
+  return g_read(L, tofile(L), 2);
+}
+
+
+static int io_readline (lua_State *L) {
+  int *f = (int *) lua_touserdata(L, lua_upvalueindex(1));
+  int sucess;
+  if (*f < 0)  /* file is already closed? */
+    luaL_error(L, "file is already closed");
+  sucess = _read_line(L, f);
+  if (sucess) return 1;
+  else {  /* EOF */
+    if (lua_toboolean(L, lua_upvalueindex(2))) {  /* generator created file? */
+      lua_settop(L, 0);
+      lua_pushvalue(L, lua_upvalueindex(1));
+      aux_close(L);  /* close it */
+    }
+    return 0;
+  }
+}
+
+/* }====================================================== */
+
+
+static int g_write (lua_State *L, int *f, int arg) {
+  int nargs = lua_gettop(L) - 1;
+  int status = 1;
+  for (; nargs--; arg++) {
+    if (lua_type(L, arg) == LUA_TNUMBER) {
+      /* optimization: could be done exactly as for strings */
+      status = status &&
+          rb->fdprintf(*f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
+    }
+    else {
+      size_t l;
+      const char *s = luaL_checklstring(L, arg, &l);
+      status = status && (rb->write(*f, s, l) == (ssize_t)l);
+    }
+  }
+  return pushresult(L, status, NULL);
+}
+
+
+static int io_write (lua_State *L) {
+  return g_write(L, getiofile(L, IO_OUTPUT), 1);
+}
+
+
+static int f_write (lua_State *L) {
+  return g_write(L, tofile(L), 2);
+}
+
+
+static int f_seek (lua_State *L) {
+  static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
+  static const char *const modenames[] = {"set", "cur", "end", NULL};
+  int f = *tofile(L);
+  int op = luaL_checkoption(L, 2, "cur", modenames);
+  long offset = luaL_optlong(L, 3, 0);
+  op = rb->lseek(f, offset, mode[op]);
+  if (op)
+    return pushresult(L, 0, NULL);  /* error */
+  else {
+    lua_pushinteger(L, rb->lseek(f, 0, SEEK_CUR));
+    return 1;
+  }
+}
+
+
+static const luaL_Reg iolib[] = {
+  {"close", io_close},
+  {"input", io_input},
+  {"lines", io_lines},
+  {"open", io_open},
+  {"output", io_output},
+  {"read", io_read},
+  {"type", io_type},
+  {"write", io_write},
+  {NULL, NULL}
+};
+
+
+static const luaL_Reg flib[] = {
+  {"close", io_close},
+  {"lines", f_lines},
+  {"read", f_read},
+  {"seek", f_seek},
+  {"write", f_write},
+  {"__gc", io_gc},
+  {"__tostring", io_tostring},
+  {NULL, NULL}
+};
+
+
+static void createmeta (lua_State *L) {
+  luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
+  lua_pushvalue(L, -1);  /* push metatable */
+  lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
+  luaL_register(L, NULL, flib);  /* file methods */
+}
+
+
+LUALIB_API int luaopen_io (lua_State *L) {
+  createmeta(L);
+  lua_replace(L, LUA_ENVIRONINDEX);
+  /* open library */
+  luaL_register(L, LUA_IOLIBNAME, iolib);
+  /* create (and set) default files */
+  lua_pop(L, 1);  /* pop environment for default files */
+  return 1;
+}