+/* Convert a string into a long long. Returns 1 if the string could be parsed
+ * into a (non-overflowing) long long, 0 otherwise. The value will be set to
+ * the parsed value when appropriate. */
+int string2ll(char *s, size_t slen, long long *value) {
+ char *p = s;
+ size_t plen = 0;
+ int negative = 0;
+ unsigned long long v;
+
+ if (plen == slen)
+ return 0;
+
+ /* Special case: first and only digit is 0. */
+ if (slen == 1 && p[0] == '0') {
+ if (value != NULL) *value = 0;
+ return 1;
+ }
+
+ if (p[0] == '-') {
+ negative = 1;
+ p++; plen++;
+
+ /* Abort on only a negative sign. */
+ if (plen == slen)
+ return 0;
+ }
+
+ /* First digit should be 1-9, otherwise the string should just be 0. */
+ if (p[0] >= '1' && p[0] <= '9') {
+ v = p[0]-'0';
+ p++; plen++;
+ } else if (p[0] == '0' && slen == 1) {
+ *value = 0;
+ return 1;
+ } else {
+ return 0;
+ }
+
+ while (plen < slen && p[0] >= '0' && p[0] <= '9') {
+ if (v > (ULLONG_MAX / 10)) /* Overflow. */
+ return 0;
+ v *= 10;
+
+ if (v > (ULLONG_MAX - (p[0]-'0'))) /* Overflow. */
+ return 0;
+ v += p[0]-'0';
+
+ p++; plen++;
+ }
+
+ /* Return if not all bytes were used. */
+ if (plen < slen)
+ return 0;
+
+ if (negative) {
+ if (v > ((unsigned long long)(-(LLONG_MIN+1))+1)) /* Overflow. */
+ return 0;
+ if (value != NULL) *value = -v;
+ } else {
+ if (v > LLONG_MAX) /* Overflow. */
+ return 0;
+ if (value != NULL) *value = v;
+ }
+ return 1;
+}
+
+/* Convert a string into a long. Returns 1 if the string could be parsed into a
+ * (non-overflowing) long, 0 otherwise. The value will be set to the parsed
+ * value when appropriate. */
+int string2l(char *s, size_t slen, long *lval) {
+ long long llval;
+
+ if (!string2ll(s,slen,&llval))
+ return 0;
+
+ if (llval < LONG_MIN || llval > LONG_MAX)
+ return 0;
+
+ *lval = (long)llval;
+ return 1;
+}
+
+/* Convert a double to a string representation. Returns the number of bytes
+ * required. The representation should always be parsable by stdtod(3). */
+int d2string(char *buf, size_t len, double value) {
+ if (isnan(value)) {
+ len = snprintf(buf,len,"nan");
+ } else if (isinf(value)) {
+ if (value < 0)
+ len = snprintf(buf,len,"-inf");
+ else
+ len = snprintf(buf,len,"inf");
+ } else if (value == 0) {
+ /* See: http://en.wikipedia.org/wiki/Signed_zero, "Comparisons". */
+ if (1.0/value < 0)
+ len = snprintf(buf,len,"-0");
+ else
+ len = snprintf(buf,len,"0");
+ } else {
+#if (DBL_MANT_DIG >= 52) && (LLONG_MAX == 0x7fffffffffffffffLL)
+ /* Check if the float is in a safe range to be casted into a
+ * long long. We are assuming that long long is 64 bit here.
+ * Also we are assuming that there are no implementations around where
+ * double has precision < 52 bit.
+ *
+ * Under this assumptions we test if a double is inside an interval
+ * where casting to long long is safe. Then using two castings we
+ * make sure the decimal part is zero. If all this is true we use
+ * integer printing function that is much faster. */
+ double min = -4503599627370495; /* (2^52)-1 */
+ double max = 4503599627370496; /* -(2^52) */
+ if (val > min && val < max && value == ((double)((long long)value)))
+ len = ll2string(buf,len,(long long)value);
+ else
+#endif
+ len = snprintf(buf,len,"%.17g",value);
+ }
+
+ return len;
+}
+
+#ifdef UTIL_TEST_MAIN
+#include <assert.h>
+
+void test_string2ll(void) {
+ char buf[32];
+ long long v;
+
+ /* May not start with +. */
+ strcpy(buf,"+1");
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+
+ /* Leading space. */
+ strcpy(buf," 1");
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+
+ /* Trailing space. */
+ strcpy(buf,"1 ");
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+
+ /* May not start with 0. */
+ strcpy(buf,"01");
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+
+ strcpy(buf,"-1");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == -1);
+
+ strcpy(buf,"0");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == 0);
+
+ strcpy(buf,"1");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == 1);
+
+ strcpy(buf,"99");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == 99);
+
+ strcpy(buf,"-99");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == -99);
+
+ strcpy(buf,"-9223372036854775808");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == LLONG_MIN);
+
+ strcpy(buf,"-9223372036854775809"); /* overflow */
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+
+ strcpy(buf,"9223372036854775807");
+ assert(string2ll(buf,strlen(buf),&v) == 1);
+ assert(v == LLONG_MAX);
+
+ strcpy(buf,"9223372036854775808"); /* overflow */
+ assert(string2ll(buf,strlen(buf),&v) == 0);
+}
+
+void test_string2l(void) {
+ char buf[32];
+ long v;
+
+ /* May not start with +. */
+ strcpy(buf,"+1");
+ assert(string2l(buf,strlen(buf),&v) == 0);
+
+ /* May not start with 0. */
+ strcpy(buf,"01");
+ assert(string2l(buf,strlen(buf),&v) == 0);
+
+ strcpy(buf,"-1");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == -1);
+
+ strcpy(buf,"0");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == 0);
+
+ strcpy(buf,"1");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == 1);
+
+ strcpy(buf,"99");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == 99);
+
+ strcpy(buf,"-99");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == -99);
+
+#if LONG_MAX != LLONG_MAX
+ strcpy(buf,"-2147483648");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == LONG_MIN);
+
+ strcpy(buf,"-2147483649"); /* overflow */
+ assert(string2l(buf,strlen(buf),&v) == 0);
+
+ strcpy(buf,"2147483647");
+ assert(string2l(buf,strlen(buf),&v) == 1);
+ assert(v == LONG_MAX);
+
+ strcpy(buf,"2147483648"); /* overflow */
+ assert(string2l(buf,strlen(buf),&v) == 0);
+#endif
+}
+
+int main(int argc, char **argv) {
+ test_string2ll();
+ test_string2l();
+ return 0;
projects / redis.git / blobdiff