Add payloads, bitmaps to trace API

This is a proposed adjustment to the trace APIs.  This makes the
trace levels into a bitmask so that they can be selectively enabled
and adds a callback-level payload, plus a message-level payload.

This makes it easier for me to a GIT_TRACE_PERF callbacks that
are simply bypassed if the PERF level is not set.

1 files changed, 30 insertions, 13 deletions

diff --git a/include/git2/trace.h b/include/git2/trace.h
index f9b4d6ff6..867b34612 100644
--- a/include/git2/trace.h
+++ b/include/git2/trace.h
@@ -20,47 +20,64 @@
 GIT_BEGIN_DECL
 
 /**
- * Available tracing levels.  When tracing is set to a particular level,
- * callers will be provided tracing at the given level and all lower levels.
+ * Available tracing messages.  Each tracing level can be enabled
+ * independently or pass GIT_TRACE_ALL to enable all levels.
  */
 typedef enum {
 	/** No tracing will be performed. */
-	GIT_TRACE_NONE = 0,
+	GIT_TRACE_NONE = 0x0000u,
+
+	/** All tracing messages will be sent. */
+	GIT_TRACE_ALL = 0xFFFFu,
 
 	/** Severe errors that may impact the program's execution */
-	GIT_TRACE_FATAL = 1,
+	GIT_TRACE_FATAL = 0x0001u,
 
 	/** Errors that do not impact the program's execution */
-	GIT_TRACE_ERROR = 2,
+	GIT_TRACE_ERROR = 0x0002u,
+	GIT_TRACE_ERROR_AND_BELOW = 0x0003u,
 
 	/** Warnings that suggest abnormal data */
-	GIT_TRACE_WARN = 3,
+	GIT_TRACE_WARN = 0x0004u,
+	GIT_TRACE_WARN_AND_BELOW = 0x0007u,
 
 	/** Informational messages about program execution */
-	GIT_TRACE_INFO = 4,
+	GIT_TRACE_INFO = 0x0008u,
+	GIT_TRACE_INFO_AND_BELOW = 0x000Fu,
 
 	/** Detailed data that allows for debugging */
-	GIT_TRACE_DEBUG = 5,
+	GIT_TRACE_DEBUG = 0x0010u,
 
 	/** Exceptionally detailed debugging data */
-	GIT_TRACE_TRACE = 6
+	GIT_TRACE_TRACE = 0x0020u,
+
+	/** Performance tracking related traces */
+	GIT_TRACE_PERF = 0x0040u,
 } git_trace_level_t;
 
 /**
  * An instance for a tracing function
  */
-typedef void (*git_trace_callback)(git_trace_level_t level, const char *msg);
+typedef void (*git_trace_callback)(
+	git_trace_level_t level, /* just one bit will be sent */
+	void *cb_payload,
+	void *msg_payload,
+	const char *msg);
 
 /**
  * Sets the system tracing configuration to the specified level with the
  * specified callback.  When system events occur at a level equal to, or
  * lower than, the given level they will be reported to the given callback.
  *
- * @param level Level to set tracing to
- * @param cb Function to call with trace data
+ * @param level Bitmask of all enabled trace levels
+ * @param cb Function to call with trace messages
+ * @param cb_payload Payload to pass when callback is invoked
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_trace_set(git_trace_level_t level, git_trace_callback cb);
+GIT_EXTERN(int) git_trace_set(
+	git_trace_level_t level,
+	git_trace_callback cb,
+	void *cb_payload);
 
 /** @} */
 GIT_END_DECL