less string operations during batch request header parsing

arangod/RestHandler/RestBatchHandler.cpp

@@ -557,7 +557,7 @@ bool RestBatchHandler::extractPart (SearchHelper* helper) {
 
     char* eol = strstr(found, "\r\n");
 
-    if (eol == 0) {
+    if (eol == nullptr) {
       breakLength = 1;
       eol = strchr(found, '\n');
 
@@ -568,27 +568,30 @@ bool RestBatchHandler::extractPart (SearchHelper* helper) {
     else {
       char* eol2 = strchr(found, '\n');
 
-      if (eol2 != 0 && eol2 < eol) {
+      if (eol2 != nullptr && eol2 < eol) {
         breakLength = 1;
         eol = eol2;
       }
     }
 
-    if (eol == 0 || eol == found) {
+    if (eol == nullptr || eol == found) {
       break;
     }
 
     // split key/value of header
     char* colon = (char*) memchr(found, (int) ':', eol - found);
 
-    if (0 == colon) {
+    if (nullptr == colon) {
       // invalid header, not containing ':'
       return false;
     }
 
-    // set up key/value pair
+    // set up the key
     string key(found, colon - found);
     StringUtils::trimInPlace(key);
+
+    if (key[0] == 'c' || key[0] == 'C') {
+      // got an interesting key. now process it
       StringUtils::tolowerInPlace(&key);
     
       // skip the colon itself
@@ -598,10 +601,11 @@ bool RestBatchHandler::extractPart (SearchHelper* helper) {
         ++colon;
       }
 
+      if ("content-type" == key) {
+        // extract the value, too
         string value(colon, eol - colon);
         StringUtils::trimInPlace(value);
 
-    if ("content-type" == key) {
         if (_partContentType == value) {
           hasTypeHeader = true;
         }
@@ -618,6 +622,7 @@ bool RestBatchHandler::extractPart (SearchHelper* helper) {
       else {
         // ignore other headers
       }
+    }
 
     found = eol + breakLength; // plus the \n
   }