static int
execute_lua_eval(lua_State *L)
{
struct lua_function_ctx *ctx = (struct lua_function_ctx *)
lua_topointer(L, 1);
struct request *request = ctx->request;
struct obuf *out = ctx->out;
struct obuf_svp *svp = &ctx->svp;
lua_settop(L, 0); /* clear the stack to simplify the logic below */
/* Compile expression */
const char *expr = request->key;
uint32_t expr_len = mp_decode_strl(&expr);
if (luaL_loadbuffer(L, expr, expr_len, "=eval")) {
diag_set(LuajitError, lua_tostring(L, -1));
lbox_error(L);
}
/* Unpack arguments */
const char *args = request->tuple;
uint32_t arg_count = mp_decode_array(&args);
luaL_checkstack(L, arg_count, "eval: out of stack");
for (uint32_t i = 0; i < arg_count; i++) {
luamp_decode(L, luaL_msgpack_default, &args);
}
/* Call compiled code */
lua_call(L, arg_count, LUA_MULTRET);
/* Send results of the called procedure to the client. */
if (iproto_prepare_select(out, svp) != 0)
diag_raise();
ctx->out_is_dirty = true;
struct mpstream stream;
mpstream_init(&stream, out, obuf_reserve_cb, obuf_alloc_cb,
luamp_error, L);
int nrets = lua_gettop(L);
for (int k = 1; k <= nrets; ++k) {
luamp_encode(L, luaL_msgpack_default, &stream, k);
}
mpstream_flush(&stream);
iproto_reply_select(out, svp, request->header->sync, nrets);
return 0;
}
struct tuple *
luaT_tuple_new(struct lua_State *L, int idx, box_tuple_format_t *format)
{
if (idx != 0 && !lua_istable(L, idx) && !luaT_istuple(L, idx)) {
diag_set(IllegalParams, "A tuple or a table expected, got %s",
lua_typename(L, lua_type(L, idx)));
return NULL;
}
struct ibuf *buf = tarantool_lua_ibuf;
ibuf_reset(buf);
struct mpstream stream;
mpstream_init(&stream, buf, ibuf_reserve_cb, ibuf_alloc_cb,
luamp_error, L);
if (idx == 0) {
/*
* Create the tuple from lua stack
* objects.
*/
int argc = lua_gettop(L);
mpstream_encode_array(&stream, argc);
for (int k = 1; k <= argc; ++k) {
luamp_encode(L, luaL_msgpack_default, &stream, k);
}
} else {
/* Create the tuple from a Lua table. */
luamp_encode_tuple(L, &tuple_serializer, &stream, idx);
}
mpstream_flush(&stream);
struct tuple *tuple = box_tuple_new(format, buf->buf,
buf->buf + ibuf_used(buf));
if (tuple == NULL)
return NULL;
ibuf_reinit(tarantool_lua_ibuf);
return tuple;
}
/**
* Tuple transforming function.
*
* Remove the fields designated by 'offset' and 'len' from an tuple,
* and replace them with the elements of supplied data fields,
* if any.
*
* Function returns newly allocated tuple.
* It does not change any parent tuple data.
*/
static int
lbox_tuple_transform(struct lua_State *L)
{
struct tuple *tuple = lua_checktuple(L, 1);
int argc = lua_gettop(L);
if (argc < 3)
luaL_error(L, "tuple.transform(): bad arguments");
lua_Integer offset = lua_tointeger(L, 2); /* Can be negative and can be > INT_MAX */
lua_Integer len = lua_tointeger(L, 3);
lua_Integer field_count = box_tuple_field_count(tuple);
/* validate offset and len */
if (offset == 0) {
luaL_error(L, "tuple.transform(): offset is out of bound");
} else if (offset < 0) {
if (-offset > field_count)
luaL_error(L, "tuple.transform(): offset is out of bound");
offset += field_count + 1;
} else if (offset > field_count) {
offset = field_count + 1;
}
if (len < 0)
luaL_error(L, "tuple.transform(): len is negative");
if (len > field_count + 1 - offset)
len = field_count + 1 - offset;
assert(offset + len <= field_count + 1);
/*
* Calculate the number of operations and length of UPDATE expression
*/
uint32_t op_cnt = 0;
if (offset < field_count + 1 && len > 0)
op_cnt++;
if (argc > 3)
op_cnt += argc - 3;
if (op_cnt == 0) {
/* tuple_update() does not accept an empty operation list. */
luaT_pushtuple(L, tuple);
return 1;
}
struct ibuf *buf = tarantool_lua_ibuf;
ibuf_reset(buf);
struct mpstream stream;
mpstream_init(&stream, buf, ibuf_reserve_cb, ibuf_alloc_cb,
luamp_error, L);
/*
* Prepare UPDATE expression
*/
mpstream_encode_array(&stream, op_cnt);
if (len > 0) {
mpstream_encode_array(&stream, 3);
mpstream_encode_str(&stream, "#");
mpstream_encode_uint(&stream, offset);
mpstream_encode_uint(&stream, len);
}
for (int i = argc ; i > 3; i--) {
mpstream_encode_array(&stream, 3);
mpstream_encode_str(&stream, "!");
mpstream_encode_uint(&stream, offset);
luamp_encode(L, luaL_msgpack_default, &stream, i);
}
mpstream_flush(&stream);
uint32_t new_size = 0, bsize;
const char *old_data = tuple_data_range(tuple, &bsize);
struct region *region = &fiber()->gc;
size_t used = region_used(region);
struct tuple *new_tuple = NULL;
/*
* Can't use box_tuple_update() since transform must reset
* the tuple format to default. The new tuple most likely
* won't coerce into the original space format, so we have
* to use the default one with no restrictions on field
* count or types.
*/
const char *new_data = tuple_update_execute(region_aligned_alloc_cb,
region, buf->buf,
buf->buf + ibuf_used(buf),
old_data, old_data + bsize,
&new_size, 1, NULL);
if (new_data != NULL)
new_tuple = tuple_new(box_tuple_format_default(),
new_data, new_data + new_size);
region_truncate(region, used);
if (new_tuple == NULL)
luaT_error(L);
luaT_pushtuple(L, new_tuple);
ibuf_reset(buf);
return 1;
}
/**
* Invoke a Lua stored procedure from the binary protocol
* (implementation of 'CALL' command code).
*/
static inline int
execute_lua_call(lua_State *L)
{
struct lua_function_ctx *ctx = (struct lua_function_ctx *)
lua_topointer(L, 1);
struct request *request = ctx->request;
struct obuf *out = ctx->out;
struct obuf_svp *svp = &ctx->svp;
lua_settop(L, 0); /* clear the stack to simplify the logic below */
const char *name = request->key;
uint32_t name_len = mp_decode_strl(&name);
int oc = 0; /* how many objects are on stack after box_lua_find */
/* Try to find a function by name in Lua */
oc = box_lua_find(L, name, name + name_len);
/* Push the rest of args (a tuple). */
const char *args = request->tuple;
uint32_t arg_count = mp_decode_array(&args);
luaL_checkstack(L, arg_count, "call: out of stack");
for (uint32_t i = 0; i < arg_count; i++)
luamp_decode(L, luaL_msgpack_default, &args);
lua_call(L, arg_count + oc - 1, LUA_MULTRET);
/**
* Add all elements from Lua stack to iproto.
*
* To allow clients to understand a complex return from
* a procedure, we are compatible with SELECT protocol,
* and return the number of return values first, and
* then each return value as a tuple.
*
* If a Lua stack contains at least one scalar, each
* value on the stack is converted to a tuple. A single
* Lua with scalars is converted to a tuple with multiple
* fields.
*
* If the stack is a Lua table, each member of which is
* not scalar, each member of the table is converted to
* a tuple. This way very large lists of return values can
* be used, since Lua stack size is limited by 8000 elements,
* while Lua table size is pretty much unlimited.
*/
/* TODO: forbid explicit yield from __serialize or __index here */
if (iproto_prepare_select(out, svp) != 0)
lbox_error(L);
ctx->out_is_dirty = true;
struct luaL_serializer *cfg = luaL_msgpack_default;
struct mpstream stream;
mpstream_init(&stream, out, obuf_reserve_cb, obuf_alloc_cb,
luamp_error, L);
uint32_t count = luamp_encode_call(L, cfg, &stream);
mpstream_flush(&stream);
iproto_reply_select(out, svp, request->header->sync, count);
return 0; /* truncate Lua stack */
}
