MINOR: hpack: move the length computation and encoding functions to .h
We'll need these functions from other inline functions, let's make them
accessible. len_to_bytes() was renamed to hpack_len_to_bytes() since it's
now exposed.
diff --git a/include/common/hpack-enc.h b/include/common/hpack-enc.h
index 23c886a..f04b78c 100644
--- a/include/common/hpack-enc.h
+++ b/include/common/hpack-enc.h
@@ -36,4 +36,46 @@
int hpack_encode_header(struct buffer *out, const struct ist n,
const struct ist v);
+/* Returns the number of bytes required to encode the string length <len>. The
+ * number of usable bits is an integral multiple of 7 plus 6 for the last byte.
+ * The maximum number of bytes returned is 4 (2097279 max length). Larger values
+ * return 0.
+ */
+static inline int hpack_len_to_bytes(size_t len)
+{
+ ssize_t slen = len;
+
+ slen -= 127;
+ if (__builtin_expect(slen < 0, 1))
+ return 1;
+ if (slen < (1 << 14)) {
+ if (__builtin_expect(slen < (1 << 7), 1))
+ return 2;
+ else
+ return 3;
+ }
+ if (slen < (1 << 21))
+ return 4;
+ return 0;
+}
+
+/* Encodes <len> into <out>+<pos> and return the new position. The caller is
+ * responsible for checking for available room using hpack_len_to_bytes()
+ * first.
+ */
+static inline int hpack_encode_len(char *out, int pos, int len)
+{
+ int code = len - 127;
+
+ if (code < 0) {
+ out[pos++] = len;
+ } else {
+ out[pos++] = 127;
+ for (; code >= 128; code >>= 7)
+ out[pos++] = code | 128;
+ out[pos++] = code;
+ }
+ return pos;
+}
+
#endif /* _COMMON_HPACK_ENC_H */