Software / code / prosody
Diff
util-src/pposix.c @ 13184:d16845afb3e2
util.pposix: Add remove_blocks() for deleting parts of files
Allows implementing e.g. a FIFO
Will probably only work on some Linux file systems like ext4.
| author | Kim Alvefur <zash@zash.se> |
|---|---|
| date | Wed, 07 Jun 2023 05:07:03 +0200 |
| parent | 13152:792f360a582b |
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--- a/util-src/pposix.c Wed Jul 12 11:42:41 2023 +0200 +++ b/util-src/pposix.c Wed Jun 07 05:07:03 2023 +0200 @@ -802,6 +802,41 @@ return 3; } +static int lc_remove_blocks(lua_State *L) { +#if defined(__linux__) + int err; + + FILE *f = *(FILE **) luaL_checkudata(L, 1, LUA_FILEHANDLE); + off_t offset = (off_t)luaL_checkinteger(L, 2); + off_t length = (off_t)luaL_checkinteger(L, 3); + + errno = 0; + + if((err = fallocate(fileno(f), FALLOC_FL_COLLAPSE_RANGE, offset, length))) { + if(errno != 0) { + /* Some old versions of Linux apparently use the return value instead of errno */ + err = errno; + } + + switch(err) { + default: /* Other issues */ + luaL_pushfail(L); + lua_pushstring(L, strerror(err)); + lua_pushinteger(L, err); + return 3; + } + } + + lua_pushboolean(L, err == 0); + return 1; +#else + luaL_pushfail(L); + lua_pushstring(L, strerror(EOPNOTSUPP)); + lua_pushinteger(L, EOPNOTSUPP); + return 3; +#endif +} + static int lc_isatty(lua_State *L) { FILE *f = *(FILE **) luaL_checkudata(L, 1, LUA_FILEHANDLE); const int fd = fileno(f); @@ -847,6 +882,7 @@ #endif { "atomic_append", lc_atomic_append }, + { "remove_blocks", lc_remove_blocks }, { "isatty", lc_isatty },
