Inline buffered reads and use memcpy for the fast path

cmdline/stream.c

@@ -435,32 +435,20 @@ ssize_t sgettok(STREAM* f, char* str, int size)
 	return i - str;
 }
 
-int sread(STREAM* f, void* void_data, size_t size)
+int sread_uncached(STREAM* f, void* void_data, size_t size)
 {
 	unsigned char* data = void_data;
 
-	/* if there is enough space in memory */
-	if (sptrlookup(f, size)) {
-		/* optimized version with all the data in memory */
-		unsigned char* pos = sptrget(f);
-
-		/* copy it */
-		while (size--)
-			*data++ = *pos++;
-
-		sptrset(f, pos);
-	} else {
-		/* standard version using sgetc() */
-		while (size--) {
-			int c = sgetc(f);
-			if (c == EOF) {
-				/* LCOV_EXCL_START */
-				return -1;
-				/* LCOV_EXCL_STOP */
-			}
-
-			*data++ = c;
+	/* standard version using sgetc() */
+	while (size--) {
+		int c = sgetc(f);
+		if (c == EOF) {
+			/* LCOV_EXCL_START */
+			return -1;
+			/* LCOV_EXCL_STOP */
 		}
+
+		*data++ = c;
 	}
 
 	return 0;

cmdline/stream.h

@@ -245,11 +245,26 @@ static inline void sungetc(int c, STREAM* s)
 		--s->pos;
 }
 
+/**
+ * \internal Used by sread() when the requested data crosses the buffered range.
+ * \note Don't call this directly, but use sread().
+ */
+int sread_uncached(STREAM* f, void* void_data, size_t size);
+
 /**
  * Read a fixed amount of chars.
  * Return 0 on success, or -1 on error.
  */
-int sread(STREAM* f, void* void_data, size_t size);
+static inline int sread(STREAM* f, void* void_data, size_t size)
+{
+	if (tommy_unlikely(!sptrlookup(f, size)))
+		return sread_uncached(f, void_data, size);
+
+	memcpy(void_data, f->pos, size);
+	f->pos += size;
+
+	return 0;
+}
 
 /**
  * Get a char from a stream, ignoring one '\r'.