From 3f0904cce89026eab8b5503fc6cd328b3fae33fa Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Thu, 28 Apr 2016 11:56:30 -0700
Subject: [PATCH] Use std::string instead of malloc strings to make mbtiles
 metadata

---
 mbtiles.cpp | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/mbtiles.cpp b/mbtiles.cpp
index 80153340..4b685458 100644
--- a/mbtiles.cpp
+++ b/mbtiles.cpp
@@ -8,6 +8,7 @@
 #include <string.h>
 #include <sqlite3.h>
 #include <vector>
+#include <string>
 #include "pool.hpp"
 #include "mbtiles.hpp"
 #include "geometry.hpp"
@@ -82,7 +83,7 @@ void mbtiles_write_tile(sqlite3 *outdb, int z, int tx, int ty, const char *data,
 	}
 }
 
-static void quote(char **buf, const char *s) {
+static void quote(std::string *buf, const char *s) {
 	char tmp[strlen(s) * 8 + 1];
 	char *out = tmp;
 
@@ -101,15 +102,10 @@ static void quote(char **buf, const char *s) {
 	}
 
 	*out = '\0';
-	*buf = (char *) realloc(*buf, strlen(*buf) + strlen(tmp) + 1);
-	if (*buf == NULL) {
-		perror("realloc");
-		exit(EXIT_FAILURE);
-	}
-	strcat(*buf, tmp);
+	buf->append(std::string(tmp));
 }
 
-static void aprintf(char **buf, const char *format, ...) {
+static void aprintf(std::string *buf, const char *format, ...) {
 	va_list ap;
 	char *tmp;
 
@@ -120,12 +116,7 @@ static void aprintf(char **buf, const char *format, ...) {
 	}
 	va_end(ap);
 
-	*buf = (char *) realloc(*buf, strlen(*buf) + strlen(tmp) + 1);
-	if (*buf == NULL) {
-		perror("Out of memory");
-		exit(EXIT_FAILURE);
-	}
-	strcat(*buf, tmp);
+	buf->append(std::string(tmp));
 	free(tmp);
 }
 
@@ -236,11 +227,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, char **layername,
 	}
 	sqlite3_free(sql);
 
-	char *buf = strdup("{");
-	if (buf == NULL) {
-		perror("Out of memory");
-		exit(EXIT_FAILURE);
-	}
+	std::string buf("{");
 	aprintf(&buf, "\"vector_layers\": [ ");
 
 	int i;
@@ -291,7 +278,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, char **layername,
 
 	aprintf(&buf, " ] }");
 
-	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('json', %Q);", buf);
+	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('json', %Q);", buf.c_str());
 	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set json: %s\n", err);
 		if (!forcetable) {
@@ -299,7 +286,6 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, char **layername,
 		}
 	}
 	sqlite3_free(sql);
-	free(buf);
 }
 
 void mbtiles_close(sqlite3 *outdb, char **argv) {