Add function to SerdSink for freeing opaque handle

This can be used to associate dynamically allocated data with a sink and have
it managed along with the sink's lifetime.

7 files changed, 23 insertions, 10 deletions

diff --git a/serd/serd.h b/serd/serd.h
index e471988c..72e64c20 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -1014,6 +1014,9 @@ serd_env_write_prefixes(const SerdEnv* env, const SerdSink* sink);
    @{
 */
 
+/// Function to free an opaque handle
+typedef void (*SerdFreeFunc)(void* ptr);
+
 /**
    Create a new sink
 
@@ -1021,10 +1024,11 @@ serd_env_write_prefixes(const SerdEnv* env, const SerdSink* sink);
    serd_sink_set_*_func functions to set handlers for various events.
 
    @param handle Opaque handle that will be passed to sink functions.
+   @param free_handle Free function to call on handle in serd_sink_free().
 */
 SERD_API
 SerdSink*
-serd_sink_new(void* handle);
+serd_sink_new(void* handle, SerdFreeFunc free_handle);
 
 /// Free `sink`
 SERD_API
diff --git a/src/sink.c b/src/sink.c
index edaf271f..498935a0 100644
--- a/src/sink.c
+++ b/src/sink.c
@@ -23,18 +23,26 @@
 #include <stdlib.h>
 
 SerdSink*
-serd_sink_new(void* handle)
+serd_sink_new(void* handle, SerdFreeFunc free_handle)
 {
 	SerdSink* sink = (SerdSink*)calloc(1, sizeof(SerdSink));
 
-	sink->handle = handle;
+	sink->handle      = handle;
+	sink->free_handle = free_handle;
+
 	return sink;
 }
 
 void
 serd_sink_free(SerdSink* sink)
 {
-	free(sink);
+	if (sink) {
+		if (sink->free_handle) {
+			sink->free_handle(sink->handle);
+		}
+
+		free(sink);
+	}
 }
 
 SerdStatus
diff --git a/src/sink.h b/src/sink.h
index 57c52021..d9b5c59c 100644
--- a/src/sink.h
+++ b/src/sink.h
@@ -24,6 +24,7 @@
 */
 struct SerdSinkImpl {
 	void*             handle;
+	SerdFreeFunc      free_handle;
 	SerdBaseFunc      base;
 	SerdPrefixFunc    prefix;
 	SerdStatementFunc statement;
diff --git a/tests/env_test.c b/tests/env_test.c
index c0629da5..ee172fff 100644
--- a/tests/env_test.c
+++ b/tests/env_test.c
@@ -86,7 +86,7 @@ test_env(void)
 	serd_node_free(blank);
 
 	size_t    n_prefixes          = 0;
-	SerdSink* count_prefixes_sink = serd_sink_new(&n_prefixes);
+	SerdSink* count_prefixes_sink = serd_sink_new(&n_prefixes, NULL);
 	serd_sink_set_prefix_func(count_prefixes_sink, count_prefixes);
 	serd_env_set_prefix(env, pre, eg);
 	serd_env_write_prefixes(env, count_prefixes_sink);
diff --git a/tests/overflow_test.c b/tests/overflow_test.c
index 4a942f58..7e545793 100644
--- a/tests/overflow_test.c
+++ b/tests/overflow_test.c
@@ -56,7 +56,7 @@ main(void)
 	                      {NULL, 0}};
 
 	SerdWorld* world = serd_world_new();
-	SerdSink*  sink  = serd_sink_new(NULL);
+	SerdSink*  sink  = serd_sink_new(NULL, NULL);
 
 	for (const Test* t = tests; t->str; ++t) {
 		const SerdStatus st = test(world, sink, t->str, t->stack_size);
diff --git a/tests/read_chunk_test.c b/tests/read_chunk_test.c
index 8ff3e03e..56c6abdc 100644
--- a/tests/read_chunk_test.c
+++ b/tests/read_chunk_test.c
@@ -74,7 +74,7 @@ int
 main(void)
 {
 	SerdWorld* world = serd_world_new();
-	SerdSink*  sink  = serd_sink_new(NULL);
+	SerdSink*  sink  = serd_sink_new(NULL, NULL);
 	serd_sink_set_base_func(sink, on_base);
 	serd_sink_set_prefix_func(sink, on_prefix);
 	serd_sink_set_statement_func(sink, on_statement);
diff --git a/tests/serd_test.c b/tests/serd_test.c
index da3780f7..3b622c7a 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -119,7 +119,7 @@ test_read_chunks(void)
 	size_t            n_statements = 0;
 	FILE* const       f            = tmpfile();
 	static const char null         = 0;
-	SerdSink*         sink         = serd_sink_new(&n_statements);
+	SerdSink*         sink         = serd_sink_new(&n_statements, NULL);
 
 	assert(sink);
 	serd_sink_set_statement_func(sink, count_statements);
@@ -202,7 +202,7 @@ test_read_string(void)
 {
 	SerdWorld*  world        = serd_world_new();
 	size_t      n_statements = 0;
-	SerdSink*   sink         = serd_sink_new(&n_statements);
+	SerdSink*   sink         = serd_sink_new(&n_statements, NULL);
 	SerdReader* reader       = serd_reader_new(world, SERD_TURTLE, sink, 4096);
 	assert(reader);
 
@@ -703,7 +703,7 @@ test_reader(const char* path)
 	SerdWorld*  world  = serd_world_new();
 
 	size_t    n_statements = 0;
-	SerdSink* sink         = serd_sink_new(&n_statements);
+	SerdSink* sink         = serd_sink_new(&n_statements, NULL);
 	serd_sink_set_statement_func(sink, count_statements);
 
 	SerdReader* reader = serd_reader_new(world, SERD_TURTLE, sink, 4096);