Minor optimization for strlen and memcpy calls for reading blend files

Summary:
This commit removes ~10000 strlen calls and ~100000 memcpy calls in blender (profiled with blender --background), ~10000 memcpy calls in makesdna.

There is no need to create null-terminated strings for atoi, because it converts only the initial portion of the string anyway.
Also it was noticed that DNA_elem_array_size and arraysize functions work only with full strings, so there is no point to calculate strlen.

Reviewers: campbellbarton

Reviewed By: campbellbarton

Differential Revision: http://developer.blender.org/D105

3 files changed, 24 insertions, 30 deletions

diff --git a/source/blender/makesdna/DNA_genfile.h b/source/blender/makesdna/DNA_genfile.h
index 96d71288c62..9a6c7144692 100644
--- a/source/blender/makesdna/DNA_genfile.h
+++ b/source/blender/makesdna/DNA_genfile.h
@@ -68,7 +68,7 @@ void DNA_struct_switch_endian(struct SDNA *oldsdna, int oldSDNAnr, char *data);
 char *DNA_struct_get_compareflags(struct SDNA *sdna, struct SDNA *newsdna);
 void *DNA_struct_reconstruct(struct SDNA *newsdna, struct SDNA *oldsdna, char *compflags, int oldSDNAnr, int blocks, void *data);
 
-int DNA_elem_array_size(const char *astr, int len);
+int DNA_elem_array_size(const char *str);
 int DNA_elem_offset(struct SDNA *sdna, const char *stype, const char *vartype, const char *name);
 
 bool DNA_struct_elem_find(struct SDNA *sdna, const char *stype, const char *vartype, const char *name);
diff --git a/source/blender/makesdna/intern/dna_genfile.c b/source/blender/makesdna/intern/dna_genfile.c
index ed7f6f5d765..eca06242da0 100644
--- a/source/blender/makesdna/intern/dna_genfile.c
+++ b/source/blender/makesdna/intern/dna_genfile.c
@@ -178,19 +178,16 @@ static int le_int(int temp)
 /**
  * parses the "[n]" on the end of an array name and returns the number of array elements n.
  */
-int DNA_elem_array_size(const char *astr, int len)
+int DNA_elem_array_size(const char *str)
 {
 	int a, mul = 1;
-	char str[100], *cp = NULL;
+	const char *cp = NULL;
 
-	memcpy(str, astr, len + 1);
-
-	for (a = 0; a < len; a++) {
+	for (a = 0; str[a]; a++) {
 		if (str[a] == '[') {
 			cp = &(str[a + 1]);
 		}
 		else if (str[a] == ']' && cp) {
-			str[a] = 0;
 			mul *= atoi(cp);
 		}
 	}
@@ -246,7 +243,7 @@ static int elementsize(const SDNA *sdna, short type, short name)
 		/* has the name an extra length? (array) */
 		mul = 1;
 		if (cp[namelen - 1] == ']') {
-			mul = DNA_elem_array_size(cp, namelen);
+			mul = DNA_elem_array_size(cp);
 		}
 		
 		len = sdna->pointerlen * mul;
@@ -255,7 +252,7 @@ static int elementsize(const SDNA *sdna, short type, short name)
 		/* has the name an extra length? (array) */
 		mul = 1;
 		if (cp[namelen - 1] == ']') {
-			mul = DNA_elem_array_size(cp, namelen);
+			mul = DNA_elem_array_size(cp);
 		}
 		
 		len = mul * sdna->typelens[type];
@@ -729,7 +726,7 @@ static void cast_elem(
 
 	eSDNA_Type ctypenr, otypenr;
 
-	arrlen = DNA_elem_array_size(name, strlen(name));
+	arrlen = DNA_elem_array_size(name);
 
 	if ( (otypenr = sdna_type_nr(otype)) == -1 ||
 	     (ctypenr = sdna_type_nr(ctype)) == -1)
@@ -820,7 +817,7 @@ static void cast_pointer(int curlen, int oldlen, const char *name, char *curdata
 #endif
 	int arrlen;
 	
-	arrlen = DNA_elem_array_size(name, strlen(name));
+	arrlen = DNA_elem_array_size(name);
 	
 	while (arrlen > 0) {
 	
@@ -990,8 +987,8 @@ static void reconstruct_elem(
 
 			if (oname[countpos] == '[' && strncmp(name, oname, countpos) == 0) {  /* basis equal */
 				
-				cursize = DNA_elem_array_size(name, strlen(name));
-				oldsize = DNA_elem_array_size(oname, strlen(oname));
+				cursize = DNA_elem_array_size(name);
+				oldsize = DNA_elem_array_size(oname);
 
 				if (ispointer(name)) {  /* handle pointer or functionpointer */
 					cast_pointer(newsdna->pointerlen, oldsdna->pointerlen,
@@ -1091,9 +1088,9 @@ static void reconstruct_struct(
 				curSDNAnr = DNA_struct_find_nr(newsdna, type);
 				
 				/* array! */
-				mul = DNA_elem_array_size(name, strlen(name));
+				mul = DNA_elem_array_size(name);
 				nameo = oldsdna->names[sppo[1]];
-				mulo = DNA_elem_array_size(nameo, strlen(nameo));
+				mulo = DNA_elem_array_size(nameo);
 				
 				eleno = elementsize(oldsdna, sppo[0], sppo[1]);
 				
@@ -1164,7 +1161,7 @@ void DNA_struct_switch_endian(SDNA *oldsdna, int oldSDNAnr, char *data)
 			if (cpo) {
 				oldSDNAnr = DNA_struct_find_nr(oldsdna, type);
 				
-				mul = DNA_elem_array_size(name, strlen(name));
+				mul = DNA_elem_array_size(name);
 				elena = elen / mul;
 
 				while (mul--) {
@@ -1178,7 +1175,7 @@ void DNA_struct_switch_endian(SDNA *oldsdna, int oldSDNAnr, char *data)
 			if (ispointer(name)) {
 				if (oldsdna->pointerlen == 8) {
 					
-					mul = DNA_elem_array_size(name, strlen(name));
+					mul = DNA_elem_array_size(name);
 					cpo = cur;
 					while (mul--) {
 						cval = cpo[0]; cpo[0] = cpo[7]; cpo[7] = cval;
@@ -1207,7 +1204,7 @@ void DNA_struct_switch_endian(SDNA *oldsdna, int oldSDNAnr, char *data)
 					}
 					
 					if (skip == false) {
-						mul = DNA_elem_array_size(name, strlen(name));
+						mul = DNA_elem_array_size(name);
 						cpo = cur;
 						while (mul--) {
 							cval = cpo[0];
@@ -1223,7 +1220,7 @@ void DNA_struct_switch_endian(SDNA *oldsdna, int oldSDNAnr, char *data)
 				           spc[0] == SDNA_TYPE_FLOAT))
 				{
 
-					mul = DNA_elem_array_size(name, strlen(name));
+					mul = DNA_elem_array_size(name);
 					cpo = cur;
 					while (mul--) {
 						cval = cpo[0];
@@ -1238,7 +1235,7 @@ void DNA_struct_switch_endian(SDNA *oldsdna, int oldSDNAnr, char *data)
 				else if ( (spc[0] == SDNA_TYPE_INT64) ||
 				          (spc[0] == SDNA_TYPE_UINT64))
 				{
-					mul = DNA_elem_array_size(name, strlen(name));
+					mul = DNA_elem_array_size(name);
 					cpo = cur;
 					while (mul--) {
 						cval = cpo[0]; cpo[0] = cpo[7]; cpo[7] = cval;
diff --git a/source/blender/makesdna/intern/makesdna.c b/source/blender/makesdna/intern/makesdna.c
index aac79245501..39bf5ec437f 100644
--- a/source/blender/makesdna/intern/makesdna.c
+++ b/source/blender/makesdna/intern/makesdna.c
@@ -201,7 +201,7 @@ static int convert_include(char *filename);
 /**
  * Determine how many bytes are needed for an array.
  */ 
-static int arraysize(char *astr, int len);
+static int arraysize(const char *str);
 
 /**
  * Determine how many bytes are needed for each struct.
@@ -699,19 +699,16 @@ static int convert_include(char *filename)
 	return 0;
 }
 
-static int arraysize(char *astr, int len)
+static int arraysize(const char *str)
 {
 	int a, mul = 1;
-	char str[100], *cp = NULL;
-
-	memcpy(str, astr, len + 1);
+	const char *cp = NULL;
 	
-	for (a = 0; a < len; a++) {
+	for (a = 0; str[a]; a++) {
 		if (str[a] == '[') {
 			cp = &(str[a + 1]);
 		}
 		else if (str[a] == ']' && cp) {
-			str[a] = 0;
 			/* if 'cp' is a preprocessor definition, it will evaluate to 0,
 			 * the caller needs to check for this case and throw an error */
 			mul *= atoi(cp);
@@ -725,7 +722,7 @@ static int calculate_structlens(int firststruct)
 {
 	int a, b, len_native, len_64, unknown = nr_structs, lastunknown, structtype, type, mul, namelen;
 	short *sp, *structpoin;
-	char *cp;
+	const char *cp;
 	int has_pointer, dna_error = 0;
 		
 	while (unknown) {
@@ -756,7 +753,7 @@ static int calculate_structlens(int firststruct)
 						has_pointer = 1;
 						/* has the name an extra length? (array) */
 						mul = 1;
-						if (cp[namelen - 1] == ']') mul = arraysize(cp, namelen);
+						if (cp[namelen - 1] == ']') mul = arraysize(cp);
 
 						if (mul == 0) {
 							printf("Zero array size found or could not parse %s: '%.*s'\n", types[structtype], namelen + 1, cp);
@@ -794,7 +791,7 @@ static int calculate_structlens(int firststruct)
 					else if (typelens_native[type]) {
 						/* has the name an extra length? (array) */
 						mul = 1;
-						if (cp[namelen - 1] == ']') mul = arraysize(cp, namelen);
+						if (cp[namelen - 1] == ']') mul = arraysize(cp);
 
 						if (mul == 0) {
 							printf("Zero array size found or could not parse %s: '%.*s'\n", types[structtype], namelen + 1, cp);