#include <Python.h>

#include <string.h>

char *
PyMem_Strndup(const char *str, size_t len)
{
	if (str != NULL) {
		char *copy = PyMem_New(char, len + 1);
		if (copy != NULL)
			memcpy(copy, str, len);
			copy[len] = '\0';
			return copy;
	}
	return NULL;
}

char *
PyMem_Strdup(const char *str)
{
	return PyMem_Strndup(str, strlen(str));
}

char *
reprn(char *str, size_t len) {
	static char strings[10240];
	static size_t current = 0;
	size_t reqlen = 2;
	char c,
		 *out,
		 *write,
		 *begin = str,
		 *end = str + len;
	while (begin < end) {
		c = *begin;
		if (c == '\'') {
			reqlen += 2;
		} else if (c == '\r') {
			reqlen += 2;
		} else if (c == '\n') {
			reqlen += 2;
		} else if (c == '\t') {
			reqlen += 2;
		} else if (c < ' ') {
			reqlen += 3;
		} else {
			reqlen++;
		}
		begin++;
	}
	if (reqlen > 10240) {
		reqlen = 10240;
	}
	if (current + reqlen > 10240) {
		current = 0;
	}
	begin = str;
	end = str + len;
	out = write = strings + current;
	*write++ = '\'';
	while (begin < end) {
		c = *begin;
		if (c == '\'') {
			if (write + 5 >= strings + 10240) break;
			sprintf(write, "\\'");
			write += 2;
		} else if (c == '\r') {
			if (write + 5 >= strings + 10240) break;
			sprintf(write, "\\r");
			write += 2;
		} else if (c == '\n') {
			if (write + 5 >= strings + 10240) break;
			sprintf(write, "\\n");
			write += 2;
		} else if (c == '\t') {
			if (write + 5 >= strings + 10240) break;
			sprintf(write, "\\t");
			write += 2;
		} else if (c < ' ') {
			if (write + 6 >= strings + 10240) break;
			sprintf(write, "\\x%02x", c);
			write += 3;
		} else {
			if (write + 4 >= strings + 10240) break;
			*write++ = c;
		}
		begin++;
	}
	*write++ = '\'';
	*write++ = '\0';
	current += (size_t)(write - out);
	return out;
}

char *
repr(char *str) {
	return reprn(str, strlen(str));
}
