foundationdb/fdbclient/JsonBuilder.cpp

#include "fdbclient/JsonBuilder.h"
#include <iostream>

JsonBuilderObject JsonBuilder::makeMessage(const char *name, const char *description) {
	JsonBuilderObject out;
	out["name"] = name;
	out["description"] = description;
	return out;
}

// dst must have at least len + 3 bytes available (".e" becomes "0.0e0")
// Returns bytes written, or 0 on failure.
int JsonBuilder::coerceAsciiNumberToJSON(const char *s, int len, char *dst) {
	if(len == 0) {
		return 0;
	}

	const char *send = s + len;
	char *wptr = dst;
	bool dot = false;

	// Allow one optional sign
	if(*s == '-') {
		*wptr++ = *s++;

		// Output not yet valid so return failure
		if(s == send) {
			return 0;
		}
	}

	// 'inf' becomes 1e99
	if(*s == 'i') {
		if(len >= 3 && (strncmp(s, "inf", 3) == 0)) {
			strcpy(wptr, "1e99");
			return 4 + wptr - dst;
		}
		// Anything else starting with 'i' is a failure
		return 0;
	}

	// Skip leading zeroes
	while(*s == '0') {
		++s;

		// If found end, number is valid and zero
		if(s == send) {
			*wptr++ = '0';
			return wptr - dst;
		}
	}

	// If a dot is found, write a zero before it
	if(*s == '.') {
		dot = true;
		*wptr++ = '0';
		*wptr++ = *s++;

		// If found end, add a zero and return
		if(s == send) {
			*wptr++ = '0';
			return wptr - dst;
		}

		// If there is no digit after the dot, write a zero
		if(!isdigit(*s)) {
			*wptr++ = '0';
		}
	}

	// Write all digits found
	while(isdigit(*s)) {
		*wptr++ = *s++;

		// If found end, number is valid so return
		if(s == send) {
			return wptr - dst;
		}

	}
	// If there is a dot, return unless its the first
	if(*s == '.') {
		if(dot) {
			return wptr - dst;
		}
		*wptr++ = *s++;

		// If found end, add a zero and return
		if(s == send) {
			*wptr++ = '0';
			return wptr - dst;
		}

		// If there are more digits write them, else write a 0
		if(isdigit(*s)) {
			do {
				*wptr++ = *s++;

				// If found end, number is valid so return
				if(s == send) {
					return wptr - dst;
				}

			} while(isdigit(*s));
		}
		else {
			*wptr++ = '0';
		}
	}
	// Now we can have an e or E, else stop
	if(*s == 'e' || *s == 'E') {
		*wptr++ = *s++;

		// If found end, add a zero and return
		if(s == send) {
			*wptr++ = '0';
			return wptr - dst;
		}

		// Allow one optional sign
		if(*s == '-' || *s == '+') {
			*wptr++ = *s++;
		}

		// If found end, add a zero and return
		if(s == send) {
			*wptr++ = '0';
			return wptr - dst;
		}

		// If there are more digits write then, else write a 0
		if(isdigit(*s)) {
			do {
				*wptr++ = *s++;

				// If found end, number is valid so return
				if(s == send) {
					return wptr - dst;
				}

			} while(isdigit(*s));
		}
		else {
			*wptr++ = '0';
		}
	}

	return wptr - dst;
}