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bf2c16ccb0
janet/core/serialize.c
Calvin Rose bf2c16ccb0 Flesh out support for userdata 
Add file reading via file objects.
Finalizer option for userdata.
2017-04-26 10:22:16 -04:00

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/*
* Copyright (c) 2017 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <gst/gst.h>
/**
* Data format
* State is encoded as a string of unsigned bytes.
*
* Types:
*
* Byte 0 to 200: small integer byte - 100
* Byte 201: Nil
* Byte 202: True
* Byte 203: False
* Byte 204: Number - double format
* Byte 205: String - [u32 length]*[u8... characters]
* Byte 206: Symbol - [u32 length]*[u8... characters]
* Byte 207: Buffer - [u32 length]*[u8... characters]
* Byte 208: Array - [u32 length]*[value... elements]
* Byte 209: Tuple - [u32 length]*[value... elements]
* Byte 210: Thread - [value parent][u8 state][u32 frames]*[[value callee][value env]
* [u32 pcoffset][u32 ret][u32 args][u32 size]*[value ...stack]]
* Byte 211: Table - [u32 length]*2*[value... kvs]
* Byte 212: FuncDef - [u32 locals][u32 arity][u32 flags][u32 literallen]*[value...
* literals][u32 bytecodelen]*[u16... bytecode]
* Byte 213: FuncEnv - [value thread][u32 length]*[value ...upvalues]
* (upvalues is not read if thread is a thread object)
* Byte 214: Func - [value parent][value def][value env]
* (nil values indicate empty)
* Byte 215: LUdata - [value meta][u32 length]*[u8... bytes]
* Byte 216: CFunc - [u32 length]*[u8... idstring]
* Byte 217: Ref - [u32 id]
* Byte 218: Integer - [i64 value]
*/
/* Error at buffer end */
static const char UEB[] = "unexpected end of buffer";
/* Read 4 bytes as an unsigned integer */
static uint32_t bytes2u32(const uint8_t *bytes) {
union {
uint8_t bytes[4];
uint32_t u32;
} u;
gst_memcpy(u.bytes, bytes, 4 * sizeof(uint8_t));
return u.u32;
}
/* Read 2 bytes as unsigned short */
static uint16_t bytes2u16(const uint8_t *bytes) {
union {
uint8_t bytes[2];
uint16_t u16;
} u;
gst_memcpy(u.bytes, bytes, 2 * sizeof(uint8_t));
return u.u16;
}
/* Read 8 bytes as a double */
static double bytes2dbl(const uint8_t *bytes) {
union {
uint8_t bytes[8];
double dbl;
} u;
gst_memcpy(u.bytes, bytes, 8 * sizeof(uint8_t));
return u.dbl;
}
/* Read 8 bytes as a integer */
static int64_t bytes2int(const uint8_t *bytes) {
union {
uint8_t bytes[8];
int64_t i;
} u;
gst_memcpy(u.bytes, bytes, 8 * sizeof(uint8_t));
return u.i;
}
/* Read a string and turn it into a gst value. Returns
* an error message if there is an error message during
* deserialization. If successful, the resulting value is
* passed by reference. */
static const char *gst_deserialize_impl(
Gst *vm,
const uint8_t *data,
const uint8_t *end,
const uint8_t **newData,
GstArray *visited,
GstValue *out) {
GstValue ret;
ret.type = GST_NIL;
GstValue *buffer;
uint32_t length, i;
const char *err;
/* Handle errors as needed */
#define deser_error(e) return (e)
/* Assertions */
#define deser_assert(c, e) do{if(!(c))deser_error(e);}while(0)
/* Assert enough buffer */
#define deser_datacheck(len) do{if (end < (data + len)) deser_error(UEB);}while(0)
/* Check for enough space to read uint32_t */
#define read_u32(out) do{deser_datacheck(4); (out)=bytes2u32(data); data += 4; }while(0)
#define read_u16(out) do{deser_datacheck(2); (out)=bytes2u16(data); data += 2; }while(0)
#define read_dbl(out) do{deser_datacheck(8); (out)=bytes2dbl(data); data += 8; }while(0)
#define read_i64(out) do{deser_datacheck(8); (out)=bytes2int(data); data += 8; }while(0)
/* Check enough buffer left to read one byte */
if (data >= end) deser_error(UEB);
/* Small integer */
if (*data < 201) {
ret.type = GST_INTEGER;
ret.data.integer = *data - 100;
*newData = data + 1;
*out = ret;
return NULL;
}
/* Main switch for types */
switch (*data++) {
default:
return "unable to deserialize";
case 201: /* Nil */
ret.type = GST_NIL;
break;
case 202: /* True */
ret.type = GST_BOOLEAN;
ret.data.boolean = 1;
break;
case 203: /* False */
ret.type = GST_BOOLEAN;
ret.data.boolean = 0;
break;
case 204: /* Long number (double) */
ret.type = GST_REAL;
read_dbl(ret.data.real);
break;
case 205: /* String */
ret.type = GST_STRING;
read_u32(length);
deser_datacheck(length);
ret.data.string = gst_string_b(vm, data, length);
data += length;
gst_array_push(vm, visited, ret);
break;
case 206: /* Struct */
ret.type = GST_STRUCT;
read_u32(length);
buffer = gst_struct_begin(vm, length);
for (i = 0; i < length; ++i) {
GstValue k, v;
if ((err = gst_deserialize_impl(vm, data, end, &data, visited, &k)))
return err;
if ((err = gst_deserialize_impl(vm, data, end, &data, visited, &v)))
return err;
gst_struct_put(buffer, k, v);
}
ret.data.st = gst_struct_end(vm, buffer);
gst_array_push(vm, visited, ret);
break;
case 207: /* Buffer */
ret.type = GST_BYTEBUFFER;
read_u32(length);
deser_datacheck(length);
ret.data.buffer = gst_alloc(vm, sizeof(GstBuffer));
ret.data.buffer->data = gst_alloc(vm, length);
gst_memcpy(ret.data.buffer->data, data, length);
ret.data.buffer->count = length;
ret.data.buffer->capacity = length;
data += length;
gst_array_push(vm, visited, ret);
break;
case 208: /* Array */
ret.type = GST_ARRAY;
read_u32(length);
buffer = gst_alloc(vm, length * sizeof(GstValue));
for (i = 0; i < length; ++i)
if ((err = gst_deserialize_impl(vm, data, end, &data, visited, buffer + i)))
return err;
ret.data.array = gst_alloc(vm, sizeof(GstArray));
ret.data.array->data = buffer;
ret.data.array->count = length;
ret.data.array->capacity = length;
gst_array_push(vm, visited, ret);
break;
case 209: /* Tuple */
ret.type = GST_TUPLE;
read_u32(length);
buffer = gst_tuple_begin(vm, length);
for (i = 0; i < length; ++i)
if ((err = gst_deserialize_impl(vm, data, end, &data, visited, buffer + i)))
return err;
ret.type = GST_TUPLE;
ret.data.tuple = gst_tuple_end(vm, buffer);
gst_array_push(vm, visited, ret);
break;
case 210: /* Thread */
{
GstThread *t;
GstValue *stack;
uint16_t prevsize = 0;
uint8_t statusbyte;
t = gst_thread(vm, gst_wrap_nil(), 64);
err = gst_deserialize_impl(vm, data, end, &data, visited, &ret);
if (err != NULL) return err;
if (ret.type != GST_THREAD) return "expected thread parent to thread";
t->parent = ret.data.thread;
ret.data.thread = t;
deser_assert(data < end, UEB);
statusbyte = *data++;
read_u32(length);
/* Check for empty thread - TODO check for valid state */
if (length == 0)
break;
/* Set status */
if (statusbyte == 0) t->status = GST_THREAD_PENDING;
else if (statusbyte == 1) t->status = GST_THREAD_ALIVE;
else t->status = GST_THREAD_DEAD;
/* Add frames */
for (i = 0; i < length; ++i) {
GstValue callee, env;
uint32_t pcoffset;
uint16_t ret, args, size, j;
/* Create a new frame */
if (i > 0)
gst_thread_beginframe(vm, t, gst_wrap_nil(), 0);
/* Read the stack */
err = gst_deserialize_impl(vm, data, end, &data, visited, &callee);
if (err != NULL) return err;
err = gst_deserialize_impl(vm, data, end, &data, visited, &env);
if (err != NULL) return err;
read_u32(pcoffset);
read_u32(ret);
read_u32(args);
read_u32(size);
/* Set up the stack */
stack = gst_thread_stack(t);
if (callee.type == GST_FUNCTION) {
gst_frame_pc(stack) = callee.data.function->def->byteCode + pcoffset;
if (env.type == GST_FUNCENV)
gst_frame_env(stack) = env.data.env;
}
gst_frame_ret(stack) = ret;
gst_frame_args(stack) = args;
gst_frame_size(stack) = size;
gst_frame_prevsize(stack) = prevsize;
prevsize = size;
/* Push stack args */
for (j = 0; j < size; ++j) {
GstValue temp;
err = gst_deserialize_impl(vm, data, end, &data, visited, &temp);
gst_thread_push(vm, t, temp);
}
}
}
break;
case 211: /* Table */
{
ret.type = GST_TABLE;
read_u32(length);
ret.data.table = gst_table(vm, 2 * length);
for (i = 0; i < length; ++i) {
GstValue key, value;
err = gst_deserialize_impl(vm, data, end, &data, visited, &key);
if (err != NULL) return err;
err = gst_deserialize_impl(vm, data, end, &data, visited, &value);
if (err != NULL) return err;
gst_table_put(vm, ret.data.table, key, value);
}
gst_array_push(vm, visited, ret);
}
break;
case 212: /* Funcdef */
{
GstFuncDef *def;
uint32_t locals, arity, literalsLen, byteCodeLen, flags;
read_u32(locals);
read_u32(arity);
read_u32(flags);
read_u32(literalsLen);
def = gst_alloc(vm, sizeof(GstFuncDef));
ret.type = GST_FUNCDEF;
ret.data.def = def;
def->locals = locals;
def->arity = arity;
def->flags = flags;
def->literalsLen = literalsLen;
if (literalsLen > 0) {
def->literals = gst_alloc(vm, literalsLen * sizeof(GstValue));
}
for (i = 0; i < literalsLen; ++i) {
err = gst_deserialize_impl(vm, data, end, &data, visited, def->literals + i);
if (err != NULL) return err;
}
read_u32(byteCodeLen);
deser_datacheck(byteCodeLen);
def->byteCode = gst_alloc(vm, byteCodeLen * sizeof(uint16_t));
def->byteCodeLen = byteCodeLen;
for (i = 0; i < byteCodeLen; ++i) {
read_u16(def->byteCode[i]);
}
gst_array_push(vm, visited, ret);
}
break;
case 213: /* Funcenv */
{
GstValue thread;
err = gst_deserialize_impl(vm, data, end, &data, visited, &thread);
if (err != NULL) return err;
read_u32(length);
ret.type = GST_FUNCENV;
ret.data.env = gst_alloc(vm, sizeof(GstFuncEnv));
ret.data.env->stackOffset = length;
if (thread.type == GST_THREAD) {
ret.data.env->thread = thread.data.thread;
} else {
ret.data.env->thread = NULL;
ret.data.env->values = gst_alloc(vm, sizeof(GstValue) * length);
for (i = 0; i < length; ++i) {
GstValue item;
err = gst_deserialize_impl(vm, data, end, &data, visited, &item);
if (err != NULL) return err;
ret.data.env->values[i] = item;
}
}
gst_array_push(vm, visited, ret);
}
break;
case 214: /* Function */
{
GstValue parent, def, env;
err = gst_deserialize_impl(vm, data, end, &data, visited, &parent);
if (err != NULL) return err;
err = gst_deserialize_impl(vm, data, end, &data, visited, &def);
if (err != NULL) return err;
err = gst_deserialize_impl(vm, data, end, &data, visited, &env);
if (err != NULL) return err;
ret.type = GST_FUNCTION;
ret.data.function = gst_alloc(vm, sizeof(GstFunction));
if (parent.type == GST_NIL) {
ret.data.function->parent = NULL;
} else if (parent.type == GST_FUNCTION) {
ret.data.function->parent = parent.data.function;
} else {
deser_error("expected function");
}
deser_assert(def.type == GST_FUNCDEF, "expected funcdef");
deser_assert(env.type == GST_FUNCENV, "expected funcenv");
ret.data.function->env = env.data.env;
ret.data.function->def = env.data.def;
gst_array_push(vm, visited, ret);
}
break;
case 215: /* LUdata */
{
/* TODO enable deserialization of userdata through registration
* to names in vm. */
}
break;
case 216: /* C function */
/* TODO - add registry for c functions */
read_u32(length);
ret.type = GST_NIL;
break;
case 217: /* Reference */
read_u32(length);
deser_assert(visited->count > length, "invalid reference");
ret = visited->data[length];
break;
case 218: /* Integer */
ret.type = GST_INTEGER;
read_i64(ret.data.integer);
break;
}
/* Handle a successful return */
*out = ret;
*newData = data;
return NULL;
}
/* Load a value from data */
const char *gst_deserialize(
Gst *vm,
const uint8_t *data,
uint32_t len,
GstValue *out,
const uint8_t *nextData) {
GstValue ret;
const char *err;
GstArray *visited = gst_array(vm, 10);
err = gst_deserialize_impl(vm, data, data + len, &nextData, visited, &ret);
if (err != NULL) return err;
*out = ret;
return NULL;
}
/* Allow appending other types to buffers */
BUFFER_DEFINE(real, GstReal)
BUFFER_DEFINE(integer, GstInteger)
BUFFER_DEFINE(u32, uint32_t)
/* Serialize a value and write to a buffer. Returns possible
* error messages. */
const char *gst_serialize_impl(
Gst *vm,
GstBuffer *buffer,
GstTable *visited,
uint32_t *nextId,
GstValue x) {
uint32_t i, count;
const char *err;
GstValue check;
#define write_byte(b) gst_buffer_push(vm, buffer, (b))
#define write_u32(b) gst_buffer_push_u32(vm, buffer, (b))
#define write_u16(b) gst_buffer_push_u16(vm, buffer, (b))
#define write_dbl(b) gst_buffer_push_real(vm, buffer, (b))
#define write_int(b) gst_buffer_push_integer(vm, buffer, (b))
/* Check non reference types - if successful, return NULL */
switch (x.type) {
case GST_NIL:
write_byte(201);
return NULL;
case GST_BOOLEAN:
write_byte(x.data.boolean ? 202 : 203);
return NULL;
case GST_REAL:
write_byte(204);
write_dbl(x.data.real);
return NULL;
case GST_INTEGER:
if (x.data.integer <= 100 && x.data.integer >= -100) {
write_byte(x.data.integer + 100);
} else {
write_byte(218);
write_int(x.data.integer);
}
return NULL;
case GST_CFUNCTION:
/* TODO */
break;
default:
break;
}
/* Check if already seen - if so, use reference */
check = gst_table_get(visited, x);
if (check.type == GST_INTEGER) {
write_byte(217);
write_u32((uint32_t) check.data.integer);
return NULL;
}
/* Check reference types */
switch (x.type) {
default:
return "unable to serialize type";
case GST_STRING:
write_byte(205);
count = gst_string_length(x.data.string);
write_u32(count);
for (i = 0; i < count; ++i) {
write_byte(x.data.string[i]);
}
break;
case GST_STRUCT:
write_byte(206);
count = gst_struct_length(x.data.st);
write_u32(count);
for (i = 0; i < gst_struct_capacity(x.data.st); i += 2) {
if (x.data.st[i].type != GST_NIL) {
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.st[i]);
if (err != NULL) return err;
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.st[i + 1]);
if (err != NULL) return err;
}
}
break;
case GST_BYTEBUFFER:
write_byte(207);
count = x.data.buffer->count;
write_u32(count);
for (i = 0; i < count; ++i) {
write_byte(x.data.buffer->data[i]);
}
break;
case GST_ARRAY:
write_byte(208);
count = x.data.array->count;
write_u32(count);
for (i = 0; i < count; ++i) {
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.array->data[i]);
if (err != NULL) return err;
}
break;
case GST_TUPLE:
write_byte(209);
count = gst_tuple_length(x.data.tuple);
write_u32(count);
for (i = 0; i < count; ++i) {
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.tuple[i]);
if (err != NULL) return err;
}
break;
case GST_THREAD:
{
GstThread *t = x.data.thread;
const GstValue *stack;
uint32_t framecount = gst_thread_countframes(t);
uint32_t i;
err = gst_serialize_impl(vm, buffer, visited, nextId, gst_wrap_thread(t->parent));
if (err != NULL) return err;
/* Write the status byte */
if (t->status == GST_THREAD_PENDING) write_byte(0);
else if (t->status == GST_THREAD_ALIVE) write_byte(1);
else write_byte(2);
/* Write number of stack frames */
write_u32(framecount);
/* Write stack frames */
for (i = 0; i < framecount; ++i) {
uint32_t j, size;
GstValue callee = gst_frame_callee(stack);
GstFuncEnv *env = gst_frame_env(stack);
err = gst_serialize_impl(vm, buffer, visited, nextId, callee);
if (err != NULL) return err;
err = gst_serialize_impl(vm, buffer, visited, nextId, gst_wrap_funcenv(env));
if (err != NULL) return err;
if (callee.type == GST_FUNCTION) {
write_u32(gst_frame_pc(stack) - callee.data.function->def->byteCode);
} else {
write_u32(0);
}
write_u32(gst_frame_ret(stack));
write_u32(gst_frame_args(stack));
size = gst_frame_size(stack);
write_u32(size);
for (j = 0; j < size; ++j) {
err = gst_serialize_impl(vm, buffer, visited, nextId, stack[j]);
if (err != NULL) return err;
}
/* Next stack frame */
stack = t->data + GST_FRAME_SIZE;
}
}
break;
case GST_TABLE:
write_byte(211);
count = x.data.table->count;
write_u32(count);
for (i = 0; i < x.data.table->capacity; i += 2) {
if (x.data.table->data[i].type == GST_NIL) continue;
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.tuple[i]);
if (err != NULL) return err;
err = gst_serialize_impl(vm, buffer, visited, nextId, x.data.tuple[i+1]);
if (err != NULL) return err;
}
break;
case GST_FUNCDEF: /* Funcdef */
{
/* TODO */
}
break;
case GST_FUNCENV: /* Funcenv */
{
/* TODO */
}
break;
case GST_FUNCTION: /* Function */
{
/* TODO */
}
break;
}
/* Record reference */
check.type = GST_INTEGER;
check.data.integer = *nextId++;
gst_table_put(vm, visited, x, check);
/* Return success */
return NULL;
}
/* Serialize an object */
const char *gst_serialize(Gst *vm, GstBuffer *buffer, GstValue x) {
uint32_t nextId = 0;
uint32_t oldCount = buffer->count;
const char *err;
GstTable *visited = gst_table(vm, 10);
err = gst_serialize_impl(vm, buffer, visited, &nextId, x);
if (err != NULL) {
buffer->count = oldCount;
}
return err;
}
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