initial import

tools/sdk/include/nghttp/nghttp2_hd_huffman.h

@@ -0,0 +1,77 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2013 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef NGHTTP2_HD_HUFFMAN_H
+#define NGHTTP2_HD_HUFFMAN_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp2/nghttp2.h>
+
+typedef enum {
+  /* FSA accepts this state as the end of huffman encoding
+     sequence. */
+  NGHTTP2_HUFF_ACCEPTED = 1,
+  /* This state emits symbol */
+  NGHTTP2_HUFF_SYM = (1 << 1),
+  /* If state machine reaches this state, decoding fails. */
+  NGHTTP2_HUFF_FAIL = (1 << 2)
+} nghttp2_huff_decode_flag;
+
+typedef struct {
+  /* huffman decoding state, which is actually the node ID of internal
+     huffman tree.  We have 257 leaf nodes, but they are identical to
+     root node other than emitting a symbol, so we have 256 internal
+     nodes [1..255], inclusive. */
+  uint8_t state;
+  /* bitwise OR of zero or more of the nghttp2_huff_decode_flag */
+  uint8_t flags;
+  /* symbol if NGHTTP2_HUFF_SYM flag set */
+  uint8_t sym;
+} nghttp2_huff_decode;
+
+typedef nghttp2_huff_decode huff_decode_table_type[16];
+
+typedef struct {
+  /* Current huffman decoding state. We stripped leaf nodes, so the
+     value range is [0..255], inclusive. */
+  uint8_t state;
+  /* nonzero if we can say that the decoding process succeeds at this
+     state */
+  uint8_t accept;
+} nghttp2_hd_huff_decode_context;
+
+typedef struct {
+  /* The number of bits in this code */
+  uint32_t nbits;
+  /* Huffman code aligned to LSB */
+  uint32_t code;
+} nghttp2_huff_sym;
+
+extern const nghttp2_huff_sym huff_sym_table[];
+extern const nghttp2_huff_decode huff_decode_table[][16];
+
+#endif /* NGHTTP2_HD_HUFFMAN_H */