Make SerdSink opaque

7 files changed, 151 insertions, 23 deletions

diff --git a/serd/serd.h b/serd/serd.h
index 3d6b046d..e4631dd4 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -100,6 +100,11 @@ typedef struct SerdReaderImpl SerdReader;
 typedef struct SerdWriterImpl SerdWriter;
 
 /**
+   An interface that receives a stream of RDF data.
+*/
+typedef struct SerdSinkImpl SerdSink;
+
+/**
    Return status code.
 */
 typedef enum {
@@ -794,17 +799,6 @@ typedef SerdStatus (*SerdEndSink)(void*           handle,
                                   const SerdNode* node);
 
 /**
-   An interface that receives a stream of RDF data.
-*/
-typedef struct SerdSink {
-	void*             handle;
-	SerdBaseSink      base;
-	SerdPrefixSink    prefix;
-	SerdStatementSink statement;
-	SerdEndSink       end;
-} SerdSink;
-
-/**
    @}
    @name World
    @{
@@ -933,6 +927,53 @@ serd_env_foreach(const SerdEnv* env,
 */
 
 /**
+   Create a new sink.
+
+   Initially, the sink has no set functions and will do nothing.  Use the
+   serd_sink_set_*_func functions to set handlers for various events.
+
+   @param handle Opaque handle that will be passed to sink functions.
+*/
+SERD_API
+SerdSink*
+serd_sink_new(void* handle);
+
+/**
+   Free `sink`.
+*/
+SERD_API
+void
+serd_sink_free(SerdSink* sink);
+
+/**
+   Set a function to be called when the base URI changes.
+*/
+SERD_API
+SerdStatus
+serd_sink_set_base_func(SerdSink* sink, SerdBaseSink base_func);
+
+/**
+   Set a function to be called when a namespace prefix is defined.
+*/
+SERD_API
+SerdStatus
+serd_sink_set_prefix_func(SerdSink* sink, SerdPrefixSink prefix_func);
+
+/**
+   Set a function to be called when a statement is emitted.
+*/
+SERD_API
+SerdStatus
+serd_sink_set_statement_func(SerdSink* sink, SerdStatementSink statement_func);
+
+/**
+   Set a function to be called when an anonymous node ends.
+*/
+SERD_API
+SerdStatus
+serd_sink_set_end_func(SerdSink* sink, SerdEndSink end_func);
+
+/**
    Set the base URI.
 
    Simple wrapper for the `SerdBaseSink` of `sink`.
diff --git a/src/n3.c b/src/n3.c
index cf2646e3..163e29b5 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -17,6 +17,7 @@
 #include "node.h"
 #include "reader.h"
 #include "serd_internal.h"
+#include "sink.h"
 #include "string_utils.h"
 #include "uri_utils.h"
 
diff --git a/src/reader.c b/src/reader.c
index fb06bdc3..9b1d9f4d 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -20,6 +20,7 @@
 #include "node.h"
 #include "serd/serd.h"
 #include "serd_internal.h"
+#include "sink.h"
 #include "stack.h"
 #include "statement.h"
 #include "system.h"
diff --git a/src/sink.c b/src/sink.c
index b0437c66..0f6faf85 100644
--- a/src/sink.c
+++ b/src/sink.c
@@ -15,20 +15,67 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-#include "serd/serd.h"
+#include "sink.h"
 
 #include "statement.h"
 
+#include "serd/serd.h"
+
+#include <stdlib.h>
+
+SerdSink*
+serd_sink_new(void* handle)
+{
+	SerdSink* sink = (SerdSink*)calloc(1, sizeof(SerdSink));
+
+	sink->handle = handle;
+	return sink;
+}
+
+void
+serd_sink_free(SerdSink* sink)
+{
+	free(sink);
+}
+
+SerdStatus
+serd_sink_set_base_func(SerdSink* sink, SerdBaseSink base_func)
+{
+	sink->base = base_func;
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_prefix_func(SerdSink* sink, SerdPrefixSink prefix_func)
+{
+	sink->prefix = prefix_func;
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_statement_func(SerdSink* sink, SerdStatementSink statement_func)
+{
+	sink->statement = statement_func;
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_end_func(SerdSink* sink, SerdEndSink end_func)
+{
+	sink->end = end_func;
+	return SERD_SUCCESS;
+}
+
 SerdStatus
 serd_sink_set_base(SerdSink* sink, const SerdNode* uri)
 {
-	return sink->base(sink->handle, uri);
+	return sink->base ? sink->base(sink->handle, uri) : SERD_SUCCESS;
 }
 
 SerdStatus
 serd_sink_set_prefix(SerdSink* sink, const SerdNode* name, const SerdNode* uri)
 {
-	return sink->prefix(sink->handle, name, uri);
+	return sink->prefix ? sink->prefix(sink->handle, name, uri) : SERD_SUCCESS;
 }
 
 SerdStatus
@@ -36,7 +83,8 @@ serd_sink_write_statement(SerdSink*                sink,
                           const SerdStatementFlags flags,
                           const SerdStatement*     statement)
 {
-	return sink->statement(sink->handle, flags, statement);
+	return sink->statement ? sink->statement(sink->handle, flags, statement)
+	                       : SERD_SUCCESS;
 }
 
 SerdStatus
@@ -49,11 +97,11 @@ serd_sink_write(SerdSink*                sink,
 {
 	const SerdStatement statement = { { subject, predicate, object, graph },
 		                              NULL };
-	return sink->statement(sink->handle, flags, &statement);
+	return serd_sink_write_statement(sink, flags, &statement);
 }
 
 SerdStatus
 serd_sink_end(SerdSink* sink, const SerdNode* node)
 {
-	return sink->end(sink->handle, node);
+	return sink->end ? sink->end(sink->handle, node) : SERD_SUCCESS;
 }
diff --git a/src/sink.h b/src/sink.h
new file mode 100644
index 00000000..03523370
--- /dev/null
+++ b/src/sink.h
@@ -0,0 +1,33 @@
+/*
+  Copyright 2011-2018 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_SINK_H
+#define SERD_SINK_H
+
+#include "serd/serd.h"
+
+/**
+   An interface that receives a stream of RDF data.
+*/
+struct SerdSinkImpl {
+	void*             handle;
+	SerdBaseSink      base;
+	SerdPrefixSink    prefix;
+	SerdStatementSink statement;
+	SerdEndSink       end;
+};
+
+#endif  // SERD_SINK_H
diff --git a/src/writer.c b/src/writer.c
index 4a5d12ab..c11920eb 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -18,6 +18,7 @@
 #include "env.h"
 #include "node.h"
 #include "serd_internal.h"
+#include "sink.h"
 #include "stack.h"
 #include "string_utils.h"
 #include "system.h"
diff --git a/tests/serd_test.c b/tests/serd_test.c
index 68c2579b..efc59aef 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -482,9 +482,9 @@ main(void)
 	serd_writer_chop_blank_prefix(writer, NULL);
 
 	SerdSink* iface = serd_writer_get_sink(writer);
-	assert(iface->base(iface->handle, lit));
-	assert(iface->prefix(iface->handle, lit, lit));
-	assert(iface->end(iface->handle, NULL));
+	assert(serd_sink_set_base(iface, lit));
+	assert(serd_sink_set_prefix(iface, lit, lit));
+	assert(serd_sink_end(iface, NULL));
 	assert(serd_writer_get_env(writer) == env);
 
 	uint8_t buf[] = { 0xEF, 0xBF, 0xBD, 0 };
@@ -568,9 +568,11 @@ main(void)
 	// Rewind and test reader
 	fseek(fd, 0, SEEK_SET);
 
-	ReaderTest  rt     = { 0, NULL };
-	SerdSink    sink   = { &rt, NULL, NULL, test_sink, NULL };
-	SerdReader* reader = serd_reader_new(world, SERD_TURTLE, &sink, 4096);
+	ReaderTest rt   = { 0, NULL };
+	SerdSink*  sink = serd_sink_new(&rt);
+	serd_sink_set_statement_func(sink, test_sink);
+
+	SerdReader* reader = serd_reader_new(world, SERD_TURTLE, sink, 4096);
 	assert(reader);
 
 	SerdNode* g = serd_new_uri("http://example.org/");
@@ -591,6 +593,7 @@ main(void)
 	serd_reader_finish(reader);
 
 	serd_reader_free(reader);
+	serd_sink_free(sink);
 	fclose(fd);
 
 	serd_env_free(env);