/* TODO: typed object support */
static void
amf0_encode_table_as_object(amf_buf *buf, lua_State *L, int idx, int ridx)
{
size_t key_len;
const char *key;
amf_buf_append_char(buf, AMF0_OBJECT);
for (lua_pushnil(L); lua_next(L, idx); lua_pop(L, 1)) {
switch (lua_type(L, -2)) {
case LUA_TNUMBER:
lua_pushvalue(L, -2);
key = lua_tolstring(L, -1, &key_len);
amf_buf_append_u16(buf, (uint16_t)key_len);
amf_buf_append(buf, key, key_len);
lua_pop(L, 1);
break;
case LUA_TSTRING:
key = lua_tolstring(L, -2, &key_len);
amf_buf_append_u16(buf, (uint16_t)key_len);
amf_buf_append(buf, key, key_len);
break;
default: continue;
}
amf0_encode(L, buf, 0, -1, ridx);
}
amf_buf_append_u16(buf, (uint16_t)0);
amf_buf_append_char(buf, AMF0_END_OF_OBJECT);
}
static int
amf0_encode_ref(amf_buf *buf, lua_State *L, int idx, int ridx)
{
int ref;
/* lookup in the ref table */
lua_pushvalue(L, idx);
lua_rawget(L, ridx);
ref = (lua_isnumber(L, -1) ? lua_tonumber(L, -1) : -1);
lua_pop(L, 1);
if (ref >= 0) {
amf_buf_append_char(buf, AMF0_REFERENCE);
if (ref > UINT16_MAX) {
luaL_error(L, "amf0 reference overflow");
}
amf_buf_append_u16(buf, ref);
} else {
save_ref(L, idx, ridx);
}
return ref;
}
static void
amf3_encode_table_as_object(lua_State *L, amf_buf *buf, int idx, int sidx, int oidx, int tidx)
{
abs_idx(L, idx);
amf_buf_append_char(buf, AMF3_OBJECT);
if (amf3_encode_ref(L, buf, idx, oidx) >= 0) {
return;
}
lua_newtable(L); /* traits table */
int members = 1;
for(lua_pushnil(L); lua_next(L, idx); lua_pop(L, 1)) {
switch (lua_type(L, -2)) {
case LUA_TNUMBER:
lua_pushvalue(L, -2);
lua_tostring(L, -1);
break;
case LUA_TSTRING:
lua_pushvalue(L, -2);
break;
default:
continue;
}
lua_rawseti(L, -4, members++);
}
amf3_encode_traits(L, buf, lua_gettop(L), sidx, tidx);
lua_pop(L, 1); /* drop the traits table */
for(lua_pushnil(L); lua_next(L, idx); lua_pop(L, 1)) {
amf3_encode(L, buf, -1, sidx, oidx, tidx);
}
}
static void
encode_hdr(lua_State *L, amf_buf *buf, int ver)
{
if(!lua_istable(L, -1)) {
luaL_error(L, "invalid header structure, must be a dense table");
}
/* name */
lua_rawgeti(L, -1, 1);
size_t len;
const char *name = lua_tolstring(L, -1, &len);
amf_buf_append_u16(buf, (uint16_t)len);
if (len > 0)
amf_buf_append(buf, name, (uint16_t)len);
lua_pop(L, 1);
/* must understand */
lua_rawgeti(L, -1, 2);
int mu = lua_toboolean(L, -1);
amf_buf_append_char(buf, (char)mu);
lua_pop(L, 1);
/* content length */
amf_buf_append_u32(buf, (uint32_t)0);
lua_rawgeti(L, -1, 3);
lua_newtable(L);
amf0_encode(L, buf, (ver == 3), -2, lua_gettop(L));
lua_pop(L, 2); /* pops the obj and ref table */
}
static int
lua_amf_buffer_write_uchar(lua_State *L)
{
amf_buf *b = luaL_checkudata(L, 1, "amf_buffer");
unsigned char c = (unsigned char)luaL_checkint(L, 2);
amf_buf_append_char(b, c);
return 0;
}
static void
amf0_encode_string(amf_buf *b, const char *s, size_t len)
{
uint16_t u16;
uint32_t u32;
if (len < UINT16_MAX) {
u16 = (uint16_t)len;
amf_buf_append_char(b, AMF0_STRING);
amf_buf_append_u16(b, u16);
amf_buf_append(b, s, u16);
} else { // long string
if (len > UINT32_MAX) {
len = UINT32_MAX;
}
u32 = (uint32_t)len;
amf_buf_append_char(b, AMF0_L_STRING);
amf_buf_append_u32(b, u32);
amf_buf_append(b, s, u32);
}
}
static void
amf0_encode_table_as_array(amf_buf *buf, lua_State *L, int idx, int ridx, int len)
{
amf_buf_append_char(buf, AMF0_STRICT_ARRAY);
amf_buf_append_u32(buf, (uint32_t)len); // array count
for (int i = 1; i <= len; i++) {
lua_pushinteger(L, i);
lua_gettable(L, idx);
amf0_encode(L, buf, 0, -1, ridx);
lua_pop(L, 1);
}
}
static void
amf3_encode_table_as_array(lua_State *L, amf_buf *buf, int idx, int sidx, int oidx, int tidx, int array_len)
{
abs_idx(L, idx);
amf_buf_append_char(buf, AMF3_ARRAY);
if (amf3_encode_ref(L, buf, idx, oidx) >=0) {
return;
}
amf_buf_append_u29(buf, (array_len << 1) | 1);
/*Send an empty string to imply no named keys*/
amf_buf_append_u29(buf, (0 << 1) | 1);
for (int i = 1; i <= array_len; i++) {
lua_rawgeti(L, idx, i);
amf3_encode(L, buf, -1, sidx, oidx, tidx);
lua_pop(L, 1);
}
}
void
amf3_encode(lua_State *L, amf_buf *buf, int idx, int sidx, int oidx, int tidx)
{
int old_top, array_len;
const char *str;
size_t str_len;
old_top = lua_gettop(L);
switch (lua_type(L, idx)) {
case LUA_TNIL: {
amf_buf_append_char(buf, AMF3_NULL);
break;
}
case LUA_TBOOLEAN: {
if (lua_toboolean(L, idx)) {
amf_buf_append_char(buf, AMF3_TRUE);
} else {
amf_buf_append_char(buf, AMF3_FALSE);
}
break;
}
case LUA_TNUMBER: {
lua_Number n = lua_tonumber(L, idx);
/* encode as double */
if (floor(n) != n || n < AMF3_MIN_INT || n > AMF3_MAX_INT) {
amf_buf_append_char(buf, AMF3_DOUBLE);
amf_buf_append_double(buf, n);
} else {
amf_buf_append_char(buf, AMF3_INTEGER);
amf_buf_append_u29(buf, (int)n);
}
break;
}
case LUA_TSTRING: {
str = lua_tolstring(L, idx, &str_len);
amf_buf_append_char(buf, AMF3_STRING);
amf3_encode_string(L, buf, idx, sidx);
break;
}
case LUA_TTABLE:
array_len = strict_array_length(L, idx);
if (array_len == 0) {
amf_buf_append_char(buf, AMF3_NULL);
} else if (array_len > 0) {
amf3_encode_table_as_array(L, buf, idx, sidx, oidx, tidx, array_len);
} else {
amf3_encode_table_as_object(L, buf, idx, sidx, oidx, tidx);
}
}
assert(lua_gettop(L) == old_top);
}
void
amf0_encode(lua_State *L, amf_buf *buf, int avmplus, int idx, int ridx)
{
int array_len, old_top, ref;
size_t len;
const char *str;
abs_idx(L, idx);
abs_idx(L, ridx);
old_top = lua_gettop(L);
switch (lua_type(L, idx)) {
case LUA_TNIL:
amf_buf_append_char(buf, AMF0_NULL);
break;
case LUA_TBOOLEAN:
amf_buf_append_char(buf, AMF0_BOOLEAN);
amf_buf_append_char(buf, lua_toboolean(L, idx) ? 1 : 0);
break;
case LUA_TNUMBER:
amf_buf_append_char(buf, AMF0_NUMBER);
amf0_encode_number(buf, lua_tonumber(L, idx));
break;
case LUA_TSTRING:
str = lua_tolstring(L, idx, &len);
amf0_encode_string(buf, str, len);
break;
case LUA_TTABLE: {
if (avmplus) {
lua_newtable(L);
lua_newtable(L);
lua_newtable(L);
int top = lua_gettop(L);
amf3_encode(L, buf, idx, top-2, top-1, top);
lua_pop(L, 3);
} else {
ref = amf0_encode_ref(buf, L, idx, ridx);
if (ref >= 0) {
break;
}
array_len = strict_array_length(L, idx);
if (array_len == 0) {
amf_buf_append_char(buf, AMF0_NULL);
} else if (array_len > 0) {
amf0_encode_table_as_array(buf, L, idx, ridx, array_len);
} else {
amf0_encode_table_as_object(buf, L, idx, ridx);
}
}
break;
}
}
assert(lua_gettop(L) == old_top);
}