util/hex.h: Reserve result space in hex_encode()

starling13 · SmallJoker · commit 1db4ae96b1a1 · 2019-04-07T12:01:42.000+02:00
Reserve enough space for the result of hex_encode() to eliminate reallocations
diff --git a/src/util/hex.h b/src/util/hex.h
@@ -26,6 +26,8 @@ static const char hex_chars[] = "0123456789abcdef";
 static inline std::string hex_encode(const char *data, unsigned int data_size)
 {
 	std::string ret;
+	ret.reserve(data_size * 2);
+	
 	char buf2[3];
 	buf2[2] = '\0';
 

Original file line number	Diff line number	Diff line change
`@@ -26,6 +26,8 @@ static const char hex_chars[] = "0123456789abcdef";`
`26`	`26`	`static inline std::string hex_encode(const char *data, unsigned int data_size)`
`27`	`27`	`{`
`28`	`28`	`std::string ret;`
	`29`	`+ ret.reserve(data_size * 2);`
	`30`	`+`
`29`	`31`	`char buf2[3];`
`30`	`32`	`buf2[2] = '\0';`
`31`	`33`