freebsd-dev/module/lua/lzio.c
Chris Williamson d99a015343 OpenZFS 7431 - ZFS Channel Programs
Authored by: Chris Williamson <chris.williamson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Don Brady <don.brady@delphix.com>
Ported-by: John Kennedy <john.kennedy@delphix.com>

OpenZFS-issue: https://www.illumos.org/issues/7431
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/dfc11533

Porting Notes:
* The CLI long option arguments for '-t' and '-m' don't parse on linux
* Switched from kmem_alloc to vmem_alloc in zcp_lua_alloc
* Lua implementation is built as its own module (zlua.ko)
* Lua headers consumed directly by zfs code moved to 'include/sys/lua/'
* There is no native setjmp/longjump available in stock Linux kernel.
  Brought over implementations from illumos and FreeBSD
* The get_temporary_prop() was adapted due to VFS platform differences
* Use of inline functions in lua parser to reduce stack usage per C call
* Skip some ZFS Test Suite ZCP tests on sparc64 to avoid stack overflow
2018-02-08 15:28:18 -08:00

75 lines
1.6 KiB
C

/* BEGIN CSTYLED */
/*
** $Id: lzio.c,v 1.35.1.1 2013/04/12 18:48:47 roberto Exp $
** Buffered streams
** See Copyright Notice in lua.h
*/
#define lzio_c
#define LUA_CORE
#include <sys/lua/lua.h>
#include "llimits.h"
#include "lmem.h"
#include "lstate.h"
#include "lzio.h"
int luaZ_fill (ZIO *z) {
size_t size;
lua_State *L = z->L;
const char *buff;
lua_unlock(L);
buff = z->reader(L, z->data, &size);
lua_lock(L);
if (buff == NULL || size == 0)
return EOZ;
z->n = size - 1; /* discount char being returned */
z->p = buff;
return cast_uchar(*(z->p++));
}
void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
z->L = L;
z->reader = reader;
z->data = data;
z->n = 0;
z->p = NULL;
}
/* --------------------------------------------------------------- read --- */
size_t luaZ_read (ZIO *z, void *b, size_t n) {
while (n) {
size_t m;
if (z->n == 0) { /* no bytes in buffer? */
if (luaZ_fill(z) == EOZ) /* try to read more */
return n; /* no more input; return number of missing bytes */
else {
z->n++; /* luaZ_fill consumed first byte; put it back */
z->p--;
}
}
m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
memcpy(b, z->p, m);
z->n -= m;
z->p += m;
b = (char *)b + m;
n -= m;
}
return 0;
}
/* ------------------------------------------------------------------------ */
char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
if (n > buff->buffsize) {
if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
luaZ_resizebuffer(L, buff, n);
}
return buff->buffer;
}
/* END CSTYLED */