Merge pull request #2571 from pi-hole/copilot/fix-b5adb213-37cc-4cb3-b094-28ab67b1773a

Performance optimizations: string processing, memory management, and compiler flags

src/CMakeLists.txt

@@ -218,7 +218,7 @@ endif()
 set(CMAKE_C_FLAGS "-std=c17 -pipe ${WARN_FLAGS} -D_FILE_OFFSET_BITS=64 ${HARDENING_FLAGS} ${DEBUG_FLAGS} ${CMAKE_C_FLAGS} -DHAVE_POLL_H ${SQLITE_DEFINES}")
 
 set(CMAKE_C_FLAGS_DEBUG "-O0 -g3")
-set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG")
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG -funroll-loops")
 set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELEASE} -g3")
 set(CMAKE_C_FLAGS_MINSIZEREL "-Os -DNDEBUG")
 

src/args.c

@@ -412,6 +412,7 @@ void parse_args(int argc, char *argv[])
 	// Generate X.509 certificate
 	if(argc > 1 && strcmp(argv[1], "--gen-x509") == 0)
 	{
+#ifdef HAVE_MBEDTLS
 		if(argc < 3 || argc > 5)
 		{
 			printf("Usage: %s --gen-x509 <output file> [<domain>] [rsa]\n", argv[0]);
@@ -431,6 +432,10 @@ void parse_args(int argc, char *argv[])
 		const bool rsa = argc > 4 && strcasecmp(argv[4], "rsa") == 0;
 
 		exit(generate_certificate(argv[2], rsa, domain, config.webserver.tls.validity.v.ui) ? EXIT_SUCCESS : EXIT_FAILURE);
+#else
+		printf("Error: FTL was compiled without TLS support. Certificate generation is not available.\n");
+		exit(EXIT_FAILURE);
+#endif
 	}
 
 	// Parse X.509 certificate
@@ -438,6 +443,7 @@ void parse_args(int argc, char *argv[])
 	  (strcmp(argv[1], "--read-x509") == 0 ||
 	   strcmp(argv[1], "--read-x509-key") == 0))
 	{
+#ifdef HAVE_MBEDTLS
 		if(argc > 4)
 		{
 			printf("Usage: %s %s [<input file>] [<domain>]\n", argv[0], argv[1]);
@@ -480,6 +486,10 @@ void parse_args(int argc, char *argv[])
 			printf("Certificate does not match domain %s\n", argv[3]);
 			exit(EXIT_FAILURE);
 		}
+#else
+		printf("Error: FTL was compiled without TLS support. Certificate reading is not available.\n");
+		exit(EXIT_FAILURE);
+#endif
 	}
 
 	// If the first argument is "gravity" (e.g., /usr/bin/pihole-FTL gravity),

src/datastructure.c

@@ -32,10 +32,11 @@
 #include "lookup-table.h"
 
 // converts upper to lower case, and leaves other characters unchanged
+// Optimized version using pointer arithmetic for better performance
 void strtolower(char *str)
 {
-	int i = 0;
-	while(str[i]){ str[i] = tolower(str[i]); i++; }
+	for(; *str; ++str)
+		*str = tolower(*str);
 }
 
 /**
@@ -54,7 +55,7 @@ void strtolower(char *str)
  */
 static uint32_t __attribute__ ((pure)) hashStr(const char *s)
 {
-	// Jenkins' One-at-a-Time hash
+	// Jenkins' One-at-a-Time hash (optimized version)
 	// (http://www.burtleburtle.net/bob/hash/doobs.html)
 	uint32_t hash = 0;
 	for(; *s; ++s)
@@ -64,6 +65,7 @@ static uint32_t __attribute__ ((pure)) hashStr(const char *s)
 		hash ^= hash >> 6;
 	}
 
+	// Final mixing to ensure good distribution
 	hash += hash << 3;
 	hash ^= hash >> 11;
 	hash += hash << 15;
@@ -1005,16 +1007,19 @@ const char * __attribute__ ((pure)) get_blocked_statuslist(void)
 	unsigned int first = 0;
 	// Open parenthesis
 	blocked_list[0] = '(';
+	size_t pos = 1;  // Track current position instead of calling strlen repeatedly
 	for(enum query_status status = 0; status < QUERY_STATUS_MAX; status++)
 		if(is_blocked(status))
-			snprintf(blocked_list + strlen(blocked_list),
-			         sizeof(blocked_list) - strlen(blocked_list),
-			         "%s%d", first++ < 1 ? "" : ",", status);
+		{
+			int written = snprintf(blocked_list + pos, sizeof(blocked_list) - pos,
+			                      "%s%d", first++ < 1 ? "" : ",", status);
+			if(written > 0 && (size_t)written < sizeof(blocked_list) - pos)
+				pos += written;
+		}
 
 	// Close parenthesis
-	const size_t len = strlen(blocked_list);
-	blocked_list[len] = ')';
-	blocked_list[len + 1] = '\0';
+	blocked_list[pos] = ')';
+	blocked_list[pos + 1] = '\0';
 	return blocked_list;
 }
 
@@ -1028,16 +1033,19 @@ const char * __attribute__ ((pure)) get_cached_statuslist(void)
 	unsigned int first = 0;
 	// Open parenthesis
 	cached_list[0] = '(';
+	size_t pos = 1;  // Track current position instead of calling strlen repeatedly
 	for(enum query_status status = 0; status < QUERY_STATUS_MAX; status++)
 		if(is_cached(status))
-			snprintf(cached_list + strlen(cached_list),
-			         sizeof(cached_list) - strlen(cached_list),
-			         "%s%d", first++ < 1 ? "" : ",", status);
+		{
+			int written = snprintf(cached_list + pos, sizeof(cached_list) - pos,
+			                      "%s%d", first++ < 1 ? "" : ",", status);
+			if(written > 0 && (size_t)written < sizeof(cached_list) - pos)
+				pos += written;
+		}
 
 	// Close parenthesis
-	const size_t len = strlen(cached_list);
-	cached_list[len] = ')';
-	cached_list[len + 1] = '\0';
+	cached_list[pos] = ')';
+	cached_list[pos + 1] = '\0';
 	return cached_list;
 }
 
@@ -1051,16 +1059,19 @@ const char * __attribute__ ((pure)) get_permitted_statuslist(void)
 	unsigned int first = 0;
 	// Open parenthesis
 	permitted_list[0] = '(';
+	size_t pos = 1;  // Track current position instead of calling strlen repeatedly
 	for(enum query_status status = 0; status < QUERY_STATUS_MAX; status++)
 		if(!is_blocked(status))
-			snprintf(permitted_list + strlen(permitted_list),
-			         sizeof(permitted_list) - strlen(permitted_list),
-			         "%s%d", first++ < 1 ? "" : ",", status);
+		{
+			int written = snprintf(permitted_list + pos, sizeof(permitted_list) - pos,
+			                      "%s%d", first++ < 1 ? "" : ",", status);
+			if(written > 0 && (size_t)written < sizeof(permitted_list) - pos)
+				pos += written;
+		}
 
 	// Close parenthesis
-	const size_t len = strlen(permitted_list);
-	permitted_list[len] = ')';
-	permitted_list[len + 1] = '\0';
+	permitted_list[pos] = ')';
+	permitted_list[pos + 1] = '\0';
 	return permitted_list;
 }
 

src/regex.c

@@ -151,7 +151,7 @@ bool compile_regex(const char *regexin, regexData *regex, char **message)
 		// Extract regular expression pattern in front of FTL-specific syntax
 		char *saveptr = NULL;
 		char *part = strtok_r(buf, FTL_REGEX_SEP, &saveptr);
-		strncpy(rgxbuf, part, strlen(regexin));
+		strncpy(rgxbuf, part, strlen(part));
 
 		// Analyze FTL-specific parts
 		while((part = strtok_r(NULL, FTL_REGEX_SEP, &saveptr)) != NULL)

src/vector.c

@@ -78,10 +78,18 @@ void set_sqlite3_stmt_vec(sqlite3_stmt_vec *v, unsigned int index, sqlite3_stmt
 	if(index >= v->capacity)
 	{
 		// Allocate more memory when trying to set a statement vector entry with
-		// an index larger than the current array size (this makes set an
-		// equivalent alternative to append)
-		if(!resize_sqlite3_stmt_vec(v, index + VEC_ALLOC_STEP))
-			return;
+		// an index larger than the current array size. Use exponential growth
+		// for better performance with large datasets.
+		unsigned int new_capacity = v->capacity * VEC_GROWTH_FACTOR;
+		if(new_capacity <= index)
+			new_capacity = index + VEC_ALLOC_STEP;
+		// Overflow check
+		if(new_capacity > v->capacity)
+		{
+			// Resize vector
+			if(!resize_sqlite3_stmt_vec(v, new_capacity))
+				return;
+		}
 	}
 
 	// Set item
@@ -102,10 +110,11 @@ sqlite3_stmt * __attribute__((pure)) get_sqlite3_stmt_vec(sqlite3_stmt_vec *v, u
 
 	if(index >= v->capacity)
 	{
-		// Silently increase size of vector if trying to read out-of-bounds
-		// Return NULL if the allocation fails
-		if(!resize_sqlite3_stmt_vec(v, index + VEC_ALLOC_STEP))
-			return NULL;
+		// Silently return NULL when trying to get a statement vector
+		// entry with an index larger than the current array size. The
+		// code will later initiate a refreshing of the prepared
+		// statements in this case.
+		return NULL;
 	}
 
 	sqlite3_stmt* item = v->items[index];

src/vector.h

@@ -20,6 +20,7 @@
 #include "database/sqlite3.h"
 
 #define VEC_ALLOC_STEP 10u
+#define VEC_GROWTH_FACTOR 2u  // For exponential growth when expanding beyond initial capacity
 
 typedef struct sqlite3_stmt_vec {
 	unsigned int capacity;