reduce flash footprint by smarter code generation #4163

firmware/util/efilib.cpp

@@ -236,8 +236,6 @@ float atoff(const char *param) {
 	return integerPart + decimal / divider;
 }
 
-#define TO_LOWER(x) (((x)>='A' && (x)<='Z') ? (x) - 'A' + 'a' : (x))
-
 bool strEqualCaseInsensitive(const char *str1, const char *str2) {
 	int len1 = strlen(str1);
 	int len2 = strlen(str2);
@@ -257,6 +255,19 @@ int mytolower(const char c) {
   return TO_LOWER(c);
 }
 
+
+int djb2lowerCase(const char *str) {
+	unsigned long hash = 5381;
+	int c;
+
+	while (c = *str++) {
+		c = TO_LOWER(c);
+		hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+	}
+
+	return hash;
+}
+
 bool strEqual(const char *str1, const char *str2) {
 	// todo: there must be a standard function?!
 	int len1 = strlen(str1);

firmware/util/efilib.h

@@ -12,6 +12,9 @@
 #include <rusefi/arrays.h>
 #endif
 
+#define TO_LOWER(x) (((x)>='A' && (x)<='Z') ? (x) - 'A' + 'a' : (x))
+int djb2lowerCase(const char *str);
+
 #define _MAX_FILLER 11
 
 // http://en.wikipedia.org/wiki/Endianness

java_tools/configuration_definition/src/main/java/com/rusefi/output/HashUtil.java

@@ -0,0 +1,17 @@
+package com.rusefi.output;
+
+public class HashUtil {
+    public static int hash(String string) {
+        return djb2lowerCase(string);
+    }
+
+    public static int djb2lowerCase(String string) {
+        int hash = 5381;
+
+        for (int i = 0; i < string.length(); i++) {
+            char c = Character.toLowerCase(string.charAt(i));
+            hash = ((hash << 5) + hash) + (byte) c/* hash * 33 + c */;
+        }
+        return hash;
+    }
+}

java_tools/configuration_definition/src/test/java/com/rusefi/test/HashTest.java

@@ -0,0 +1,16 @@
+package com.rusefi.test;
+
+import com.rusefi.output.HashUtil;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class HashTest {
+    @Test
+    public void testdjb2() {
+        assertEquals(HashUtil.djb2lowerCase("Hello1"), 30950378);
+        assertEquals(HashUtil.djb2lowerCase("Hello2"), 30950379);
+        assertEquals(HashUtil.djb2lowerCase("HELLO2"), 30950379);
+    }
+
+}

unit_tests/tests/util/test_hash.cpp

@@ -0,0 +1,8 @@
+#include "pch.h"
+//#include "efilib.h"
+
+TEST(util, hash) {
+	ASSERT_EQ(djb2lowerCase("Hello1"), 30950378);
+	ASSERT_EQ(djb2lowerCase("Hello2"), 30950379);
+	ASSERT_EQ(djb2lowerCase("HELLO2"), 30950379);
+}

unit_tests/tests/util/test_util.mk

@@ -3,6 +3,7 @@
 CPPSRC += 	$(PROJECT_DIR)/../unit_tests/tests/util/test_buffered_writer.cpp \
 	$(PROJECT_DIR)/../unit_tests/tests/util/test_error_accumulator.cpp \
 	$(PROJECT_DIR)/../unit_tests/tests/util/test_exp_average.cpp \
+	$(PROJECT_DIR)/../unit_tests/tests/util/test_hash.cpp \
 	
 INCDIR += $(PROJECT_DIR)/controllers/system