From fd2ce1e76190eaffe581ed7c9b0e7e6ab84cb68d Mon Sep 17 00:00:00 2001
From: Kim Alvefur <zash@zash.se>
Date: Sat, 28 Jul 2012 22:21:10 +0200
Subject: util.pposix: Add fallocate method, backed by either posix_fallocate()
or Linux fallocate()
---
util-src/pposix.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/util-src/pposix.c b/util-src/pposix.c
index 65f8b4ab..7600766f 100644
--- a/util-src/pposix.c
+++ b/util-src/pposix.c
@@ -32,8 +32,14 @@
#include <string.h>
#include <errno.h>
#include "lua.h"
+#include "lualib.h"
#include "lauxlib.h"
+#include <fcntl.h>
+#if defined(_GNU_SOURCE)
+#include <linux/falloc.h>
+#endif
+
#if (defined(_SVID_SOURCE) && !defined(WITHOUT_MALLINFO))
#include <malloc.h>
#define WITH_MALLINFO
@@ -642,6 +648,39 @@ int lc_meminfo(lua_State* L)
}
#endif
+/* File handle extraction blatantly stolen from
+ * https://github.com/rrthomas/luaposix/blob/master/lposix.c#L631
+ * */
+
+#if _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L || defined(_GNU_SOURCE)
+int lc_fallocate(lua_State* L)
+{
+ off_t offset, len;
+ FILE *f = *(FILE**) luaL_checkudata(L, 1, LUA_FILEHANDLE);
+
+ offset = luaL_checkinteger(L, 2);
+ len = luaL_checkinteger(L, 3);
+
+#if defined(_GNU_SOURCE)
+ if(fallocate(fileno(f), FALLOC_FL_KEEP_SIZE, offset, len) != 0)
+#elif _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L
+ if(posix_fallocate(fileno(f), offset, len) != 0)
+#endif
+ {
+#if ! defined(_GNU_SOURCE)
+ /* posix_fallocate() can leave a bunch of NULs at the end, so we cut that
+ * this assumes that offset == length of the file */
+ ftruncate(fileno(f), offset);
+#endif
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ return 2;
+ }
+ lua_pushboolean(L, 1);
+ return 1;
+}
+#endif
+
/* Register functions */
int luaopen_util_pposix(lua_State *L)
@@ -679,6 +718,10 @@ int luaopen_util_pposix(lua_State *L)
{ "meminfo", lc_meminfo },
#endif
+#if _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L || defined(_GNU_SOURCE)
+ { "fallocate", lc_fallocate },
+#endif
+
{ NULL, NULL }
};
--
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