/**
* Convert a tuple into lua table. Named fields are stored as
* {name = value} pairs. Not named fields are stored as
* {1-based_index_in_tuple = value}.
*/
static int
lbox_tuple_to_map(struct lua_State *L)
{
int argc = lua_gettop(L);
if (argc < 1 || argc > 2)
goto error;
bool names_only = false;
if (argc == 2) {
if (!lua_istable(L, 2))
goto error;
lua_getfield(L, 2, "names_only");
if (!lua_isboolean(L, -1) && !lua_isnil(L, -1))
goto error;
names_only = lua_toboolean(L, -1);
}
struct tuple *tuple = lua_checktuple(L, 1);
struct tuple_format *format = tuple_format(tuple);
const char *pos = tuple_data(tuple);
int field_count = (int)mp_decode_array(&pos);
int n_named = format->dict->name_count;
lua_createtable(L, field_count, n_named);
int named_and_presented = MIN(field_count, n_named);
for (int i = 0; i < named_and_presented; ++i) {
/* Access by name. */
const char *name = format->dict->names[i];
lua_pushstring(L, name);
luamp_decode(L, luaL_msgpack_default, &pos);
lua_rawset(L, -3);
if (names_only)
continue;
/*
* Access the same field by an index. There is no
* copy for tables - lua optimizes it and uses
* references.
*/
lua_pushstring(L, name);
lua_rawget(L, -2);
lua_rawseti(L, -2, i + TUPLE_INDEX_BASE);
}
if (names_only)
return 1;
/* Access for not named fields by index. */
for (int i = n_named; i < field_count; ++i) {
luamp_decode(L, luaL_msgpack_default, &pos);
lua_rawseti(L, -2, i + TUPLE_INDEX_BASE);
}
return 1;
error:
luaL_error(L, "Usage: tuple:tomap(opts)");
return 1;
}
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;
}
static int
lbox_tuple_slice_wrapper(struct lua_State *L)
{
box_tuple_iterator_t *it = (box_tuple_iterator_t *)
lua_topointer(L, 1);
uint32_t start = lua_tonumber(L, 2);
uint32_t end = lua_tonumber(L, 3);
assert(end >= start);
const char *field;
uint32_t field_no = start;
field = box_tuple_seek(it, start);
while (field && field_no < end) {
luamp_decode(L, luaL_msgpack_default, &field);
++field_no;
field = box_tuple_next(it);
}
assert(field_no == end);
return end - start;
}
/**
* Find a tuple field by JSON path. If a field was not found and a
* path contains JSON syntax errors, then an exception is raised.
* @param L Lua state.
* @param tuple 1-th argument on a lua stack, tuple to get field
* from.
* @param path 2-th argument on lua stack. Can be field name or a
* JSON path to a field.
*
* @retval not nil Found field value.
* @retval nil A field is NULL or does not exist.
*/
static int
lbox_tuple_field_by_path(struct lua_State *L)
{
struct tuple *tuple = luaT_istuple(L, 1);
/* Is checked in Lua wrapper. */
assert(tuple != NULL);
assert(lua_isstring(L, 2));
size_t len;
const char *field = NULL, *path = lua_tolstring(L, 2, &len);
if (len == 0)
return 0;
field = tuple_field_raw_by_full_path(tuple_format(tuple),
tuple_data(tuple),
tuple_field_map(tuple),
path, (uint32_t)len,
lua_hashstring(L, 2));
if (field == NULL)
return 0;
luamp_decode(L, luaL_msgpack_default, &field);
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 */
}
