dash/lib/univalue_read.cpp

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// Copyright 2014 BitPay Inc.
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <string.h>
#include <vector>
#include <stdio.h>
#include "univalue.h"
using namespace std;
// convert hexadecimal string to unsigned integer
static const char *hatoui(const char *first, const char *last,
unsigned int& out)
{
unsigned int result = 0;
for (; first != last; ++first)
{
int digit;
if (isdigit(*first))
digit = *first - '0';
else if (*first >= 'a' && *first <= 'f')
digit = *first - 'a' + 10;
else if (*first >= 'A' && *first <= 'F')
digit = *first - 'A' + 10;
else
break;
result = 16 * result + digit;
}
out = result;
return first;
}
enum jtokentype getJsonToken(string& tokenVal, unsigned int& consumed,
const char *raw)
{
tokenVal.clear();
consumed = 0;
const char *rawStart = raw;
while ((*raw) && (isspace(*raw))) // skip whitespace
raw++;
switch (*raw) {
case 0:
return JTOK_NONE;
case '{':
raw++;
consumed = (raw - rawStart);
return JTOK_OBJ_OPEN;
case '}':
raw++;
consumed = (raw - rawStart);
return JTOK_OBJ_CLOSE;
case '[':
raw++;
consumed = (raw - rawStart);
return JTOK_ARR_OPEN;
case ']':
raw++;
consumed = (raw - rawStart);
return JTOK_ARR_CLOSE;
case ':':
raw++;
consumed = (raw - rawStart);
return JTOK_COLON;
case ',':
raw++;
consumed = (raw - rawStart);
return JTOK_COMMA;
case 'n':
case 't':
case 'f':
if (!strncmp(raw, "null", 4)) {
raw += 4;
consumed = (raw - rawStart);
return JTOK_KW_NULL;
} else if (!strncmp(raw, "true", 4)) {
raw += 4;
consumed = (raw - rawStart);
return JTOK_KW_TRUE;
} else if (!strncmp(raw, "false", 5)) {
raw += 5;
consumed = (raw - rawStart);
return JTOK_KW_FALSE;
} else
return JTOK_ERR;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': {
// part 1: int
string numStr;
const char *first = raw;
const char *firstDigit = first;
if (!isdigit(*firstDigit))
firstDigit++;
if ((*firstDigit == '0') && isdigit(firstDigit[1]))
return JTOK_ERR;
numStr += *raw; // copy first char
raw++;
if ((*first == '-') && (!isdigit(*raw)))
return JTOK_ERR;
while ((*raw) && isdigit(*raw)) { // copy digits
numStr += *raw;
raw++;
}
// part 2: frac
if (*raw == '.') {
numStr += *raw; // copy .
raw++;
if (!isdigit(*raw))
return JTOK_ERR;
while ((*raw) && isdigit(*raw)) { // copy digits
numStr += *raw;
raw++;
}
}
// part 3: exp
if (*raw == 'e' || *raw == 'E') {
numStr += *raw; // copy E
raw++;
if (*raw == '-' || *raw == '+') { // copy +/-
numStr += *raw;
raw++;
}
if (!isdigit(*raw))
return JTOK_ERR;
while ((*raw) && isdigit(*raw)) { // copy digits
numStr += *raw;
raw++;
}
}
tokenVal = numStr;
consumed = (raw - rawStart);
return JTOK_NUMBER;
}
case '"': {
raw++; // skip "
string valStr;
while (*raw) {
if (*raw < 0x20)
return JTOK_ERR;
else if (*raw == '\\') {
raw++; // skip backslash
switch (*raw) {
case '"': valStr += "\""; break;
case '\\': valStr += "\\"; break;
case '/': valStr += "/"; break;
case 'b': valStr += "\b"; break;
case 'f': valStr += "\f"; break;
case 'n': valStr += "\n"; break;
case 'r': valStr += "\r"; break;
case 't': valStr += "\t"; break;
case 'u': {
unsigned int codepoint;
if (hatoui(raw + 1, raw + 1 + 4, codepoint) !=
raw + 1 + 4)
return JTOK_ERR;
if (codepoint <= 0x7f)
valStr.push_back((char)codepoint);
else if (codepoint <= 0x7FF) {
valStr.push_back((char)(0xC0 | (codepoint >> 6)));
valStr.push_back((char)(0x80 | (codepoint & 0x3F)));
} else if (codepoint <= 0xFFFF) {
valStr.push_back((char)(0xE0 | (codepoint >> 12)));
valStr.push_back((char)(0x80 | ((codepoint >> 6) & 0x3F)));
valStr.push_back((char)(0x80 | (codepoint & 0x3F)));
}
raw += 4;
break;
}
default:
return JTOK_ERR;
}
raw++; // skip esc'd char
}
else if (*raw == '"') {
raw++; // skip "
break; // stop scanning
}
else {
valStr += *raw;
raw++;
}
}
tokenVal = valStr;
consumed = (raw - rawStart);
return JTOK_STRING;
}
default:
return JTOK_ERR;
}
}
bool UniValue::read(const char *raw)
{
clear();
bool expectName = false;
bool expectColon = false;
vector<UniValue*> stack;
string tokenVal;
unsigned int consumed;
enum jtokentype tok = JTOK_NONE;
enum jtokentype last_tok = JTOK_NONE;
do {
last_tok = tok;
tok = getJsonToken(tokenVal, consumed, raw);
if (tok == JTOK_NONE || tok == JTOK_ERR)
return false;
raw += consumed;
switch (tok) {
case JTOK_OBJ_OPEN:
case JTOK_ARR_OPEN: {
VType utyp = (tok == JTOK_OBJ_OPEN ? VOBJ : VARR);
if (!stack.size()) {
if (utyp == VOBJ)
setObject();
else
setArray();
stack.push_back(this);
} else {
UniValue tmpVal(utyp);
UniValue *top = stack.back();
top->values.push_back(tmpVal);
UniValue *newTop = &(top->values.back());
stack.push_back(newTop);
}
if (utyp == VOBJ)
expectName = true;
break;
}
case JTOK_OBJ_CLOSE:
case JTOK_ARR_CLOSE: {
if (!stack.size() || expectColon || (last_tok == JTOK_COMMA))
return false;
VType utyp = (tok == JTOK_OBJ_CLOSE ? VOBJ : VARR);
UniValue *top = stack.back();
if (utyp != top->getType())
return false;
stack.pop_back();
expectName = false;
break;
}
case JTOK_COLON: {
if (!stack.size() || expectName || !expectColon)
return false;
UniValue *top = stack.back();
if (top->getType() != VOBJ)
return false;
expectColon = false;
break;
}
case JTOK_COMMA: {
if (!stack.size() || expectName || expectColon ||
(last_tok == JTOK_COMMA) || (last_tok == JTOK_ARR_OPEN))
return false;
UniValue *top = stack.back();
if (top->getType() == VOBJ)
expectName = true;
break;
}
case JTOK_KW_NULL:
case JTOK_KW_TRUE:
case JTOK_KW_FALSE: {
if (!stack.size() || expectName || expectColon)
return false;
UniValue tmpVal;
switch (tok) {
case JTOK_KW_NULL:
// do nothing more
break;
case JTOK_KW_TRUE:
tmpVal.setBool(true);
break;
case JTOK_KW_FALSE:
tmpVal.setBool(false);
break;
default: /* impossible */ break;
}
UniValue *top = stack.back();
top->values.push_back(tmpVal);
break;
}
case JTOK_NUMBER: {
if (!stack.size() || expectName || expectColon)
return false;
UniValue tmpVal(VNUM, tokenVal);
UniValue *top = stack.back();
top->values.push_back(tmpVal);
break;
}
case JTOK_STRING: {
if (!stack.size())
return false;
UniValue *top = stack.back();
if (expectName) {
top->keys.push_back(tokenVal);
expectName = false;
expectColon = true;
} else {
UniValue tmpVal(VSTR, tokenVal);
top->values.push_back(tmpVal);
}
break;
}
default:
return false;
}
} while (!stack.empty ());
/* Check that nothing follows the initial construct (parsed above). */
tok = getJsonToken(tokenVal, consumed, raw);
if (tok != JTOK_NONE)
return false;
return true;
}