All remaining files in src/common belong to the event loop.

1 files changed, 118 insertions, 0 deletions

diff --git a/src/lib/evloop/token_bucket.h b/src/lib/evloop/token_bucket.h
new file mode 100644
index 0000000000..787317fa1f
--- /dev/null
+++ b/src/lib/evloop/token_bucket.h
@@ -0,0 +1,118 @@
+/* Copyright (c) 2018-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file token_bucket_rw.h
+ * \brief Headers for token_bucket_rw.c
+ **/
+
+#ifndef TOR_TOKEN_BUCKET_H
+#define TOR_TOKEN_BUCKET_H
+
+#include "lib/cc/torint.h"
+#include "lib/testsupport/testsupport.h"
+
+/** Largest allowable burst value for a token buffer. */
+#define TOKEN_BUCKET_MAX_BURST INT32_MAX
+
+/** A generic token buffer configuration: determines the number of tokens
+ * added to the bucket in each time unit (the "rate"), and the maximum number
+ * of tokens in the bucket (the "burst") */
+typedef struct token_bucket_cfg_t {
+  uint32_t rate;
+  int32_t burst;
+} token_bucket_cfg_t;
+
+/** A raw token bucket, decoupled from its configuration and timestamp. */
+typedef struct token_bucket_raw_t {
+  int32_t bucket;
+} token_bucket_raw_t;
+
+void token_bucket_cfg_init(token_bucket_cfg_t *cfg,
+                           uint32_t rate,
+                           uint32_t burst);
+
+void token_bucket_raw_adjust(token_bucket_raw_t *bucket,
+                             const token_bucket_cfg_t *cfg);
+
+void token_bucket_raw_reset(token_bucket_raw_t *bucket,
+                            const token_bucket_cfg_t *cfg);
+
+int token_bucket_raw_dec(token_bucket_raw_t *bucket,
+                         ssize_t n);
+
+int token_bucket_raw_refill_steps(token_bucket_raw_t *bucket,
+                                  const token_bucket_cfg_t *cfg,
+                                  const uint32_t elapsed_steps);
+
+static inline size_t token_bucket_raw_get(const token_bucket_raw_t *bucket);
+/** Return the current number of bytes set in a token bucket. */
+static inline size_t
+token_bucket_raw_get(const token_bucket_raw_t *bucket)
+{
+  return bucket->bucket >= 0 ? bucket->bucket : 0;
+}
+
+/** A convenience type containing all the pieces needed for a coupled
+ * read-bucket and write-bucket that have the same rate limit, and which use
+ * "timestamp units" (see compat_time.h) for their time. */
+typedef struct token_bucket_rw_t {
+  token_bucket_cfg_t cfg;
+  token_bucket_raw_t read_bucket;
+  token_bucket_raw_t write_bucket;
+  uint32_t last_refilled_at_timestamp;
+} token_bucket_rw_t;
+
+void token_bucket_rw_init(token_bucket_rw_t *bucket,
+                          uint32_t rate,
+                          uint32_t burst,
+                          uint32_t now_ts);
+
+void token_bucket_rw_adjust(token_bucket_rw_t *bucket,
+                            uint32_t rate, uint32_t burst);
+
+void token_bucket_rw_reset(token_bucket_rw_t *bucket,
+                           uint32_t now_ts);
+
+#define TB_READ 1
+#define TB_WRITE 2
+
+int token_bucket_rw_refill(token_bucket_rw_t *bucket,
+                           uint32_t now_ts);
+
+int token_bucket_rw_dec_read(token_bucket_rw_t *bucket,
+                             ssize_t n);
+int token_bucket_rw_dec_write(token_bucket_rw_t *bucket,
+                              ssize_t n);
+
+int token_bucket_rw_dec(token_bucket_rw_t *bucket,
+                        ssize_t n_read, ssize_t n_written);
+
+static inline size_t token_bucket_rw_get_read(const token_bucket_rw_t *bucket);
+static inline size_t
+token_bucket_rw_get_read(const token_bucket_rw_t *bucket)
+{
+  return token_bucket_raw_get(&bucket->read_bucket);
+}
+
+static inline size_t token_bucket_rw_get_write(
+                                            const token_bucket_rw_t *bucket);
+static inline size_t
+token_bucket_rw_get_write(const token_bucket_rw_t *bucket)
+{
+  return token_bucket_raw_get(&bucket->write_bucket);
+}
+
+#ifdef TOKEN_BUCKET_PRIVATE
+
+/* To avoid making the rates too small, we consider units of "steps",
+ * where a "step" is defined as this many timestamp ticks.  Keep this
+ * a power of two if you can. */
+#define TICKS_PER_STEP 16
+
+STATIC uint32_t rate_per_sec_to_rate_per_step(uint32_t rate);
+
+#endif
+
+#endif /* TOR_TOKEN_BUCKET_H */
+