mirror of
https://github.com/janet-lang/janet
synced 2024-11-15 05:04:49 +00:00
552 lines
19 KiB
C
552 lines
19 KiB
C
#include <gst/gst.h>
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/**
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* Data format
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* State is encoded as a string of unsigned bytes.
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*
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* Types:
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*
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* Byte 0 to 200: small integer byte - 100
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* Byte 201: Nil
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* Byte 202: True
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* Byte 203: False
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* Byte 204: Number - double format
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* Byte 205: String - [u32 length]*[u8... characters]
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* Byte 206: Symbol - [u32 length]*[u8... characters]
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* Byte 207: Buffer - [u32 length]*[u8... characters]
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* Byte 208: Array - [u32 length]*[value... elements]
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* Byte 209: Tuple - [u32 length]*[value... elements]
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* Byte 210: Thread - [u8 state][u32 frames]*[[value callee][value env]
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* [u32 pcoffset][u32 erroffset][u16 ret][u16 errloc][u16 size]*[value ...stack]
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* Byte 211: Object - [value parent][u32 length]*2*[value... kvs]
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* Byte 212: FuncDef - [u32 locals][u32 arity][u32 flags][u32 literallen]*[value...
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* literals][u32 bytecodelen]*[u16... bytecode]
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* Byte 213: FunEnv - [value thread][u32 length]*[value ...upvalues]
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* (upvalues is not read if thread is a thread object)
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* Byte 214: Func - [value parent][value def][value env]
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* (nil values indicate empty)
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* Byte 215: LUdata - [value meta][u32 length]*[u8... bytes]
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* Byte 216: CFunc - [u32 length]*[u8... idstring]
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* Byte 217: Ref - [u32 id]
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*/
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/* Error at buffer end */
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static const char UEB[] = "unexpected end of buffer";
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/* Read 4 bytes as an unsigned integer */
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static uint32_t bytes2u32(const uint8_t *bytes) {
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union {
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uint8_t bytes[4];
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uint32_t u32;
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} u;
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gst_memcpy(u.bytes, bytes, 4 * sizeof(uint8_t));
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return u.u32;
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}
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/* Read 2 bytes as unsigned short */
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static uint16_t bytes2u16(const uint8_t *bytes) {
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union {
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uint8_t bytes[2];
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uint16_t u16;
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} u;
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gst_memcpy(u.bytes, bytes, 2 * sizeof(uint8_t));
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return u.u16;
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}
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/* Read 8 bytes as a double */
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static uint32_t bytes2dbl(const uint8_t *bytes) {
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union {
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uint8_t bytes[8];
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double dbl;
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} u;
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gst_memcpy(u.bytes, bytes, 8 * sizeof(uint8_t));
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return u.dbl;
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}
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/* Read a string and turn it into a gst value. Returns
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* an error message if there is an error message during
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* deserialization. If successful, the resulting value is
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* passed by reference. */
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static const char *gst_deserialize_impl(
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Gst *vm,
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const uint8_t *data,
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const uint8_t *end,
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const uint8_t **newData,
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GstArray *visited,
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GstValue *out) {
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GstValue ret;
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ret.type = GST_NIL;
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GstValue *buffer;
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uint32_t length, i;
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const char *err;
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/* Handle errors as needed */
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#define deser_error(e) return (e)
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/* Assertions */
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#define deser_assert(c, e) do{if(!(c))deser_error(e);}while(0)
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/* Assert enough buffer */
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#define deser_datacheck(len) do{if (end < (data + len)) deser_error(UEB);}while(0)
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/* Check for enough space to read uint32_t */
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#define read_u32(out) do{deser_datacheck(4); (out)=bytes2u32(data); data += 4; }while(0)
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#define read_u16(out) do{deser_datacheck(2); (out)=bytes2u16(data); data += 2; }while(0)
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#define read_dbl(out) do{deser_datacheck(8); (out)=bytes2dbl(data); data += 8; }while(0)
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/* Check enough buffer left to read one byte */
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if (data >= end) deser_error(UEB);
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/* Small integer */
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if (*data < 201) {
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ret.type = GST_NUMBER;
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ret.data.number = *data - 100;
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*newData = data + 1;
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*out = ret;
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return NULL;
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}
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/* Main switch for types */
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switch (*data++) {
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default:
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return "unable to deserialize";
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case 201: /* Nil */
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ret.type = GST_NIL;
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break;
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case 202: /* True */
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ret.type = GST_BOOLEAN;
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ret.data.boolean = 1;
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break;
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case 203: /* False */
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ret.type = GST_BOOLEAN;
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ret.data.boolean = 0;
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break;
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case 204: /* Long number (double) */
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ret.type = GST_NUMBER;
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read_dbl(ret.data.number);
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break;
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case 205: /* String */
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ret.type = GST_STRING;
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read_u32(length);
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deser_datacheck(length);
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ret.data.string = gst_string_b(vm, data, length);
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data += length;
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gst_array_push(vm, visited, ret);
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break;
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case 206: /* Struct */
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ret.type = GST_STRUCT;
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read_u32(length);
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buffer = gst_struct_begin(vm, length);
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for (i = 0; i < length; ++i) {
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GstValue k, v;
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if ((err = gst_deserialize_impl(vm, data, end, &data, visited, &k)))
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return err;
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if ((err = gst_deserialize_impl(vm, data, end, &data, visited, &v)))
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return err;
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gst_struct_put(buffer, k, v);
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}
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ret.data.st = gst_struct_end(vm, buffer);
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gst_array_push(vm, visited, ret);
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break;
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case 207: /* Buffer */
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ret.type = GST_BYTEBUFFER;
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read_u32(length);
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deser_datacheck(length);
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ret.data.buffer = gst_alloc(vm, sizeof(GstBuffer));
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ret.data.buffer->data = gst_alloc(vm, length);
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gst_memcpy(ret.data.buffer->data, data, length);
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ret.data.buffer->count = length;
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ret.data.buffer->capacity = length;
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data += length;
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gst_array_push(vm, visited, ret);
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break;
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case 208: /* Array */
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ret.type = GST_ARRAY;
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read_u32(length);
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buffer = gst_alloc(vm, length * sizeof(GstValue));
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for (i = 0; i < length; ++i)
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if ((err = gst_deserialize_impl(vm, data, end, &data, visited, buffer + i)))
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return err;
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ret.data.array = gst_alloc(vm, sizeof(GstArray));
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ret.data.array->data = buffer;
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ret.data.array->count = length;
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ret.data.array->capacity = length;
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gst_array_push(vm, visited, ret);
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break;
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case 209: /* Tuple */
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ret.type = GST_TUPLE;
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read_u32(length);
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buffer = gst_tuple_begin(vm, length);
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for (i = 0; i < length; ++i)
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if ((err = gst_deserialize_impl(vm, data, end, &data, visited, buffer + i)))
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return err;
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ret.type = GST_TUPLE;
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ret.data.tuple = gst_tuple_end(vm, buffer);
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gst_array_push(vm, visited, ret);
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break;
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case 210: /* Thread */
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{
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GstValue nil;
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GstThread *t;
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GstValue *stack;
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uint16_t prevsize = 0;
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uint8_t statusbyte;
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nil.type = GST_NIL;
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t = gst_thread(vm, nil, 64);
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ret.type = GST_THREAD;
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ret.data.thread = t;
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deser_assert(data < end, UEB);
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statusbyte = *data++;
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read_u32(length);
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/* Check for empty thread - TODO check for valid state */
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if (length == 0)
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break;
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/* Set status */
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if (statusbyte == 0) t->status = GST_THREAD_PENDING;
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else if (statusbyte == 1) t->status = GST_THREAD_ALIVE;
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else t->status = GST_THREAD_DEAD;
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/* Add frames */
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for (i = 0; i < length; ++i) {
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GstValue callee, env;
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uint32_t pcoffset, erroffset;
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uint16_t ret, errloc, size, j;
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/* Create a new frame */
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if (i > 0)
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gst_thread_beginframe(vm, t, nil, 0);
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/* Read the stack */
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err = gst_deserialize_impl(vm, data, end, &data, visited, &callee);
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if (err != NULL) return err;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &env);
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if (err != NULL) return err;
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read_u32(pcoffset);
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read_u32(erroffset);
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read_u16(ret);
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read_u16(errloc);
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read_u16(size);
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/* Set up the stack */
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stack = gst_thread_stack(t);
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if (callee.type == GST_FUNCTION) {
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gst_frame_pc(stack) = callee.data.function->def->byteCode + pcoffset;
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gst_frame_errjmp(stack) = callee.data.function->def->byteCode + erroffset;
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if (env.type == GST_FUNCENV)
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gst_frame_env(stack) = env.data.env;
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}
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gst_frame_ret(stack) = ret;
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gst_frame_errloc(stack) = errloc;
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gst_frame_size(stack) = size;
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gst_frame_prevsize(stack) = prevsize;
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prevsize = size;
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/* Push stack args */
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for (j = 0; j < size; ++j) {
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GstValue temp;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &temp);
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gst_thread_push(vm, t, temp);
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}
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}
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}
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break;
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case 211: /* Object */
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{
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GstValue parent;
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ret.type = GST_OBJECT;
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ret.data.object = gst_object(vm, 10);
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err = gst_deserialize_impl(vm, data, end, &data, visited, &parent);
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if (err != NULL) return err;
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read_u32(length);
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for (i = 0; i < length; i += 2) {
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GstValue key, value;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &key);
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if (err != NULL) return err;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &value);
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if (err != NULL) return err;
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gst_object_put(vm, ret.data.object, key, value);
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}
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if (parent.type == GST_OBJECT)
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ret.data.object->parent = parent.data.object;
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gst_array_push(vm, visited, ret);
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}
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break;
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case 212: /* Funcdef */
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{
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GstFuncDef *def;
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uint32_t locals, arity, literalsLen, byteCodeLen, flags;
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read_u32(locals);
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read_u32(arity);
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read_u32(flags);
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read_u32(literalsLen);
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def = gst_alloc(vm, sizeof(GstFuncDef));
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ret.type = GST_FUNCDEF;
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ret.data.def = def;
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def->locals = locals;
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def->arity = arity;
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def->flags = flags;
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def->literalsLen = literalsLen;
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if (literalsLen > 0) {
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def->literals = gst_alloc(vm, literalsLen * sizeof(GstValue));
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}
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for (i = 0; i < literalsLen; ++i) {
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err = gst_deserialize_impl(vm, data, end, &data, visited, def->literals + i);
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if (err != NULL) return err;
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}
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read_u32(byteCodeLen);
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deser_datacheck(byteCodeLen);
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def->byteCode = gst_alloc(vm, byteCodeLen * sizeof(uint16_t));
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def->byteCodeLen = byteCodeLen;
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for (i = 0; i < byteCodeLen; ++i) {
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read_u16(def->byteCode[i]);
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}
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gst_array_push(vm, visited, ret);
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}
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break;
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case 213: /* Funcenv */
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{
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GstValue thread;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &thread);
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if (err != NULL) return err;
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read_u32(length);
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ret.type = GST_FUNCENV;
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ret.data.env = gst_alloc(vm, sizeof(GstFuncEnv));
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ret.data.env->stackOffset = length;
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if (thread.type == GST_THREAD) {
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ret.data.env->thread = thread.data.thread;
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} else {
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ret.data.env->thread = NULL;
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ret.data.env->values = gst_alloc(vm, sizeof(GstValue) * length);
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for (i = 0; i < length; ++i) {
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GstValue item;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &item);
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if (err != NULL) return err;
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ret.data.env->values[i] = item;
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}
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}
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gst_array_push(vm, visited, ret);
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}
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break;
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case 214: /* Function */
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{
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GstValue parent, def, env;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &parent);
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if (err != NULL) return err;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &def);
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if (err != NULL) return err;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &env);
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if (err != NULL) return err;
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ret.type = GST_FUNCTION;
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ret.data.function = gst_alloc(vm, sizeof(GstFunction));
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if (parent.type == GST_NIL) {
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ret.data.function->parent = NULL;
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} else if (parent.type == GST_FUNCTION) {
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ret.data.function->parent = parent.data.function;
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} else {
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deser_error("expected function");
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}
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deser_assert(def.type == GST_FUNCDEF, "expected funcdef");
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deser_assert(env.type == GST_FUNCENV, "expected funcenv");
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ret.data.function->env = env.data.env;
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ret.data.function->def = env.data.def;
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gst_array_push(vm, visited, ret);
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}
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break;
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case 215: /* LUdata */
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{
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GstValue meta;
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ret.type = GST_USERDATA;
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err = gst_deserialize_impl(vm, data, end, &data, visited, &meta);
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if (err != NULL) return err;
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deser_assert(meta.type == GST_STRUCT, "userdata requires valid meta struct");
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read_u32(length);
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deser_datacheck(length);
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ret.data.pointer = gst_userdata(vm, length, meta.data.st);
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gst_memcpy(ret.data.pointer, data, length);
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gst_array_push(vm, visited, ret);
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}
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break;
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case 216: /* C function */
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/* TODO - add registry for c functions */
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read_u32(length);
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ret.type = GST_NIL;
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break;
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case 217: /* Reference */
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read_u32(length);
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deser_assert(visited->count > length, "invalid reference");
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ret = visited->data[length];
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break;
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}
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/* Handle a successful return */
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*out = ret;
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*newData = data;
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return NULL;
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}
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/* Load a value from data */
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const char *gst_deserialize(
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Gst *vm,
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const uint8_t *data,
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uint32_t len,
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GstValue *out,
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const uint8_t *nextData) {
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GstValue ret;
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const char *err;
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GstArray *visited = gst_array(vm, 10);
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err = gst_deserialize_impl(vm, data, data + len, &nextData, visited, &ret);
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if (err != NULL) return err;
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*out = ret;
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return NULL;
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}
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/* Allow appending other types to buffers */
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BUFFER_DEFINE(number, GstNumber)
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/*BUFFER_DEFINE(u16, uint16_t)*/
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BUFFER_DEFINE(u32, uint32_t)
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/* Serialize a value and write to a buffer. Returns possible
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* error messages. */
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const char *gst_serialize_impl(
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Gst *vm,
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GstBuffer *buffer,
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GstObject *visited,
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uint32_t *nextId,
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GstValue x) {
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uint32_t i, count;
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const char *err;
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GstValue check;
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#define write_byte(b) gst_buffer_push(vm, buffer, (b))
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#define write_u32(b) gst_buffer_push_u32(vm, buffer, (b))
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#define write_u16(b) gst_buffer_push_u16(vm, buffer, (b))
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#define write_dbl(b) gst_buffer_push_number(vm, buffer, (b))
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/* Check non reference types - if successful, return NULL */
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switch (x.type) {
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case GST_NIL:
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write_byte(201);
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return NULL;
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case GST_BOOLEAN:
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write_byte(x.data.boolean ? 202 : 203);
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return NULL;
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case GST_NUMBER:
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{
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GstNumber number = x.data.number;
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int32_t int32Num = (int32_t) number;
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if (number == (GstNumber) int32Num &&
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int32Num <= 100 && int32Num >= -100) {
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write_byte(int32Num + 100);
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} else {
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write_byte(204);
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write_dbl(number);
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}
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}
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return NULL;
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case GST_CFUNCTION:
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/* TODO */
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break;
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default:
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break;
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}
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/* Check if already seen - if so, use reference */
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check = gst_object_get(visited, x);
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if (check.type == GST_NUMBER) {
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write_byte(217);
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write_u32((uint32_t) check.data.number);
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return NULL;
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}
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/* Check reference types */
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switch (x.type) {
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default:
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return "unable to serialize type";
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case GST_STRING:
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write_byte(205);
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count = gst_string_length(x.data.string);
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write_u32(count);
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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:*/
|
|
/*break;*/
|
|
}
|
|
|
|
/* Record reference */
|
|
check.type = GST_NUMBER;
|
|
check.data.number = *nextId++;
|
|
gst_object_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;
|
|
GstObject *visited = gst_object(vm, 10);
|
|
err = gst_serialize_impl(vm, buffer, visited, &nextId, x);
|
|
if (err != NULL) {
|
|
buffer->count = oldCount;
|
|
}
|
|
return err;
|
|
}
|