1 files changed, 89 insertions, 0 deletions
diff --git a/src/common/compress.h b/src/common/compress.h
new file mode 100644
index 0000000000..59c8b7b9b5
--- /dev/null
+++ b/src/common/compress.h
@@ -0,0 +1,89 @@
+/* Copyright (c) 2003, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2017, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file compress.h
+ * \brief Headers for compress.c
+ **/
+
+#ifndef TOR_COMPRESS_H
+#define TOR_COMPRESS_H
+
+/** Enumeration of what kind of compression to use.  Only ZLIB_METHOD and
+ * GZIP_METHOD is guaranteed to be supported by the compress/uncompress
+ * functions here. Call tor_compress_supports_method() to check if a given
+ * compression schema is supported by Tor. */
+typedef enum {
+  NO_METHOD=0, // This method must be first.
+  GZIP_METHOD=1,
+  ZLIB_METHOD=2,
+  LZMA_METHOD=3,
+  ZSTD_METHOD=4,
+  UNKNOWN_METHOD=5, // This method must be last. Add new ones in the middle.
+} compress_method_t;
+
+/**
+ * Enumeration to define tradeoffs between memory usage and compression level.
+ * BEST_COMPRESSION saves the most bandwidth; LOW_COMPRESSION saves the most
+ * memory.
+ **/
+typedef enum {
+  BEST_COMPRESSION, HIGH_COMPRESSION, MEDIUM_COMPRESSION, LOW_COMPRESSION
+} compression_level_t;
+
+int tor_compress(char **out, size_t *out_len,
+                 const char *in, size_t in_len,
+                 compress_method_t method);
+
+int tor_uncompress(char **out, size_t *out_len,
+                   const char *in, size_t in_len,
+                   compress_method_t method,
+                   int complete_only,
+                   int protocol_warn_level);
+
+compress_method_t detect_compression_method(const char *in, size_t in_len);
+
+int tor_compress_is_compression_bomb(size_t size_in, size_t size_out);
+
+int tor_compress_supports_method(compress_method_t method);
+unsigned tor_compress_get_supported_method_bitmask(void);
+const char *compression_method_get_name(compress_method_t method);
+const char *compression_method_get_human_name(compress_method_t method);
+compress_method_t compression_method_get_by_name(const char *name);
+
+const char *tor_compress_version_str(compress_method_t method);
+
+const char *tor_compress_header_version_str(compress_method_t method);
+
+size_t tor_compress_get_total_allocation(void);
+
+/** Return values from tor_compress_process; see that function's documentation
+ * for details. */
+typedef enum {
+  TOR_COMPRESS_OK,
+  TOR_COMPRESS_DONE,
+  TOR_COMPRESS_BUFFER_FULL,
+  TOR_COMPRESS_ERROR
+} tor_compress_output_t;
+
+/** Internal state for an incremental compression/decompression. */
+typedef struct tor_compress_state_t tor_compress_state_t;
+
+tor_compress_state_t *tor_compress_new(int compress,
+                                       compress_method_t method,
+                                       compression_level_t level);
+
+tor_compress_output_t tor_compress_process(tor_compress_state_t *state,
+                                           char **out, size_t *out_len,
+                                           const char **in, size_t *in_len,
+                                           int finish);
+void tor_compress_free(tor_compress_state_t *state);
+
+size_t tor_compress_state_size(const tor_compress_state_t *state);
+
+void tor_compress_init(void);
+
+#endif // TOR_COMPRESS_H.
+