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#include "benc.h"
#include "log.h"
#include <errno.h>
#include <stdlib.h>
#include <assert.h>
#include <ctype.h>
#include <string.h>
#define MAX(a, b) \
({ \
__typeof__ (a) _a = (a); \
__typeof__ (b) _b = (b); \
_a > _b ? _a : _b; \
})
#define MIN(a, b) \
({ \
__typeof__ (a) _a = (a); \
__typeof__ (b) _b = (b); \
_a < _b ? _a : _b; \
})
bool readint(const char** loc, int64_t* val) {
char* end = NULL;
errno = 0;
*val = strtol(*loc, &end, 10);
*loc = end;
return errno == 0;
}
bool digit(const char c) {
return c >= '0' && c <= '9';
}
char* nodenames[] = {
"INT",
"STR",
"LIST",
"DICT",
"END",
};
void indent(int depth) {
for(int i = 0; i < depth; i++) {
printf(" ");
}
}
void benc_print(const struct benc_node* stream, size_t stream_len, int* depth) {
const struct benc_node* cursor = stream;
for(; cursor < stream + stream_len; cursor++) {
switch(cursor->type) {
case BNT_INT:
indent(*depth);
printf("INT %.*s\n", cursor->size, cursor->loc);
break;
case BNT_STRING:
indent(*depth);
bool allprint = true;
for (const char* c = cursor->loc; c < cursor->loc + cursor->size; c++) {
if(!isalnum(*c)) {
allprint = false;
break;
}
}
printf("STR ");
if(allprint) {
printf("%.*s", cursor->size, cursor->loc);
} else {
for (const unsigned char* c = (const unsigned char*)cursor->loc; c < (unsigned char*)(cursor->loc + cursor->size); c++) {
printf("\\x%02X", *c);
}
}
printf("\n");
break;
case BNT_LIST:
indent(*depth);
printf("LIST\n");
*depth = cursor->depth + 1;
break;
case BNT_DICT:
indent(*depth);
printf("DICT\n");
*depth = cursor->depth + 1;
break;
case BNT_END:
*depth = cursor->depth;
indent(*depth);
printf("END\n");
break;
}
}
}
int64_t benc_decode(const char** cursor, const char* end, int* depth, struct benc_node* stream, size_t stream_len) {
size_t cursor_out = 0;
while(cursor_out < stream_len) {
struct benc_node* node = &stream[cursor_out];
if(**cursor == 'i') {
node->type = BNT_INT;
(*cursor)++;
if(*cursor >= end) {
return -cursor_out;
}
node->loc = *cursor;
while(**cursor != 'e') {
if(**cursor != '-' && !digit(**cursor)) {
return -cursor_out;
}
(*cursor)++;
if(*cursor >= end) {
return -cursor_out;
}
}
node->size = *cursor - node->loc;
(*cursor)++;
} else if(**cursor == 'l') {
node->type = BNT_LIST;
node->depth = *depth;
(*depth)++;
node->loc = *cursor;
(*cursor)++;
if(*cursor >= end) {
return -cursor_out;
}
} else if(**cursor == 'd') {
node->type = BNT_DICT;
node->depth = *depth;
(*depth)++;
node->loc = *cursor;
(*cursor)++;
if(*cursor >= end) {
return -cursor_out;
}
} else if(**cursor == 'e') {
node->type = BNT_END;
(*depth)--;
node->depth = *depth;
node->loc = *cursor;
(*cursor)++;
} else if(digit(**cursor)) {
node->type = BNT_STRING;
int64_t val;
bool rc = readint(cursor, &val);
node->size = val;
if(*cursor >= end) {
return -cursor_out;
}
assert(rc);
if(**cursor != ':') {
return -cursor_out;
}
(*cursor)++;
if(*cursor >= end) {
return -cursor_out;
}
node->loc = *cursor;
(*cursor) += node->size;
if(*cursor > end) {
return -cursor_out;
}
} else {
return -cursor_out;
dbg("Failing on char \"%c\"", **cursor);
assert(false);
}
cursor_out++;
if(*depth == 0) break;
}
return cursor_out;
}
void skip_sibling(const struct benc_node** cursor, const struct benc_node* end) {
assert((*cursor)->type == BNT_LIST || (*cursor)->type == BNT_DICT);
if((*cursor)->type == BNT_LIST || (*cursor)->type == BNT_DICT) {
uint32_t tdepth = (*cursor)->depth;
(*cursor)++;
while(true) {
if(*cursor == end) {
fatal("Invalid dict");
}
if((*cursor)->type == BNT_END && (*cursor)->depth == tdepth) {
break;
}
(*cursor)++;
}
(*cursor)++;
} else {
(*cursor)++;
}
}
// All the arrays should be equal length
ssize_t skip_to_key(const struct benc_node** cursor, const struct benc_node* end, const enum benc_nodetype* keyTypes, const char** keyValues, const size_t* keyLengths, const size_t keys) {
// @ROBUSTNESS: Check if keytypes are anything but strings and ints because that is not supported
while(true) {
if(*cursor > end-1) {
fatal("Invalid dict");
}
// Skip lists
if((*cursor)->type == BNT_LIST || (*cursor)->type == BNT_DICT) {
skip_sibling(cursor, end);
} else {
for(size_t i = 0; i < keys; i++) {
if((*cursor)->type == keyTypes[i] && memcmp((*cursor)->loc, keyValues[i], MIN((*cursor)->size, keyLengths[i])) == 0) {
return i;
}
}
}
(*cursor) += 2;
if((*cursor-1)->type == BNT_LIST || (*cursor-1)->type == BNT_DICT) {
(*cursor)--;
skip_sibling(cursor, end);
}
if((*cursor)->type == BNT_END) {
return -1;
}
}
}
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