Add writer API.

git-svn-id: http://svn.drobilla.net/serd/trunk@14 490d8e77-9747-427b-9fa3-0b8f29cee8a0

4 files changed, 121 insertions, 35 deletions

diff --git a/serd/serd.h b/serd/serd.h
index d59e3002..1dd49c65 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -55,6 +55,7 @@ extern "C" {
 
 typedef struct SerdNamespacesImpl* SerdNamespaces;  ///< Set of namespaces
 typedef struct SerdReaderImpl*     SerdReader;      ///< RDF reader
+typedef struct SerdWriterImpl*     SerdWriter;      ///< RDF writer
 
 /** RDF syntax */
 typedef enum {
@@ -182,10 +183,10 @@ serd_namespaces_add(SerdNamespaces    ns,
 /** Expand @a qname. */
 SERD_API
 bool
-serd_namespaces_expand(SerdNamespaces     ns,
-                       const SerdString*  qname,
-                       SerdChunk*         uri_prefix,
-                       SerdChunk*         uri_suffix);
+serd_namespaces_expand(const SerdNamespaces ns,
+                       const SerdString*    qname,
+                       SerdChunk*           uri_prefix,
+                       SerdChunk*           uri_suffix);
 
 /** @} */
 /** @name Reader
@@ -241,16 +242,38 @@ serd_reader_free(SerdReader reader);
  * @{
  */
 
-/** Write a node to @a file. */
+/** Create a new RDF writer. */
+SERD_API
+SerdWriter
+serd_writer_new(SerdSyntax     syntax,
+                SerdNamespaces ns,
+                FILE*          file,
+                const SerdURI* base_uri);
+
+/** Free @a writer. */
+SERD_API
+void
+serd_writer_free(SerdWriter writer);
+
+/** Set the base URI of writer. */
+SERD_API
+void
+serd_writer_set_base_uri(SerdWriter     writer,
+                         const SerdURI* uri);
+
+/** Write a statement. */
 SERD_API
 bool
-serd_write_node(FILE*             file,
-                const SerdURI*    base_uri,
-                SerdNamespaces    ns,
-                SerdNodeType      type,
-                const SerdString* str,
-                const SerdString* datatype,
-                const SerdString* lang);
+serd_writer_write_statement(SerdWriter        writer,
+                            const SerdString* graph,
+                            const SerdString* subject,
+                            SerdNodeType      subject_type,
+                            const SerdString* predicate,
+                            SerdNodeType      predicate_type,
+                            const SerdString* object,
+                            SerdNodeType      object_type,
+                            const SerdString* object_datatype,
+                            const SerdString* object_lang);
 
 /** @} */
 
diff --git a/src/namespaces.c b/src/namespaces.c
index 6c400a3c..409c92b9 100644
--- a/src/namespaces.c
+++ b/src/namespaces.c
@@ -93,10 +93,10 @@ serd_namespaces_add(SerdNamespaces    ns,
 
 SERD_API
 bool
-serd_namespaces_expand(SerdNamespaces    ns,
-                       const SerdString* qname,
-                       SerdChunk*        uri_prefix,
-                       SerdChunk*        uri_suffix)
+serd_namespaces_expand(const SerdNamespaces ns,
+                       const SerdString*    qname,
+                       SerdChunk*           uri_prefix,
+                       SerdChunk*           uri_suffix)
 {
 	const uint8_t* colon = memchr((const char*)qname->buf, ':', qname->n_bytes);
 	if (!colon) {
diff --git a/src/serdi.c b/src/serdi.c
index 13fdb2af..abac1010 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -22,7 +22,7 @@
 #include "serd/serd.h"
 
 typedef struct {
-	FILE*          out_fd;
+	SerdWriter     writer;
 	SerdNamespaces ns;
 	SerdString*    base_uri_str;
 	SerdURI        base_uri;
@@ -61,8 +61,9 @@ event_base(void*             handle,
 
 	// Replace the old base URI
 	serd_string_free(state->base_uri_str);
-	state->base_uri_str = base_uri_str;
-	state->base_uri     = base_uri;
+	state->base_uri_str     = base_uri_str;
+	state->base_uri         = base_uri;
+	serd_writer_set_base_uri(state->writer, &base_uri);
 
 	return true;
 }
@@ -105,17 +106,12 @@ event_statement(void*             handle,
                 const SerdString* object_lang)
 {
 	State* const state = (State*)handle;
-	FILE* const  fd    = state->out_fd;
-	serd_write_node(fd, &state->base_uri, state->ns,
-	                subject_type, subject, NULL, NULL);
-	fwrite(" ", 1, 1, fd);
-	serd_write_node(fd, &state->base_uri, state->ns,
-	                predicate_type, predicate, NULL, NULL);
-	fwrite(" ", 1, 1, fd);
-	serd_write_node(fd, &state->base_uri, state->ns,
-	                object_type, object, object_datatype, object_lang);
-	fwrite(" .\n", 1, 3, fd);
-	return true;
+	return serd_writer_write_statement(
+		state->writer,
+		graph,
+		subject,   subject_type,
+		predicate, predicate_type,
+		object,    object_type,    object_datatype, object_lang);
 }
 
 int
@@ -146,7 +142,11 @@ main(int argc, char** argv)
 		return 1;
 	}
 
-	State state = { out_fd, serd_namespaces_new(), serd_string_new(base_uri_str), base_uri };
+	SerdNamespaces ns = serd_namespaces_new();
+	State state = { serd_writer_new(SERD_NTRIPLES, ns, out_fd, &base_uri),
+	                ns,
+	                serd_string_new(base_uri_str),
+	                base_uri };
 
 	SerdReader reader = serd_reader_new(
 		SERD_TURTLE, &state, event_base, event_prefix, event_statement);
@@ -155,6 +155,7 @@ main(int argc, char** argv)
 	serd_reader_free(reader);
 	fclose(in_fd);
 	serd_namespaces_free(state.ns);
+	serd_writer_free(state.writer);
 	serd_string_free(state.base_uri_str);
 
 	if (success) {
diff --git a/src/write.c b/src/write.c
index 633655d8..893062ef 100644
--- a/src/write.c
+++ b/src/write.c
@@ -20,6 +20,13 @@
 
 #include "serd/serd.h"
 
+struct SerdWriterImpl {
+	SerdSyntax     syntax;
+	SerdNamespaces ns;
+	FILE*          fd;
+	SerdURI        base_uri;
+};
+
 static size_t
 file_sink(const uint8_t* buf, size_t len, void* stream)
 {
@@ -107,14 +114,16 @@ serd_write_ascii(const uint8_t* utf8, size_t n_bytes, FILE* out_fd, const uint8_
 
 SERD_API
 bool
-serd_write_node(FILE*             fd,
-                const SerdURI*    base_uri,
-                SerdNamespaces    ns,
+serd_write_node(SerdWriter        writer,
                 SerdNodeType      type,
                 const SerdString* str,
                 const SerdString* datatype,
                 const SerdString* lang)
 {
+	FILE* const    fd       = writer->fd;
+	const SerdURI* base_uri = &writer->base_uri;
+	SerdNamespaces ns       = writer->ns;
+
 	SerdChunk uri_prefix;
 	SerdChunk uri_suffix;
 	switch (type) {
@@ -161,10 +170,63 @@ serd_write_node(FILE*             fd,
 			fwrite("\"", 1, 1, fd);
 		} else if (datatype) {
 			fwrite("^^", 1, 2, fd);
-			serd_write_node(fd, base_uri, ns, URI, datatype, NULL, NULL);
+			serd_write_node(writer, URI, datatype, NULL, NULL);
 		}
 		break;
 	}
 	return true;
 }
 
+SERD_API
+bool
+serd_writer_write_statement(SerdWriter        writer,
+                            const SerdString* graph,
+                            const SerdString* subject,
+                            SerdNodeType      subject_type,
+                            const SerdString* predicate,
+                            SerdNodeType      predicate_type,
+                            const SerdString* object,
+                            SerdNodeType      object_type,
+                            const SerdString* object_datatype,
+                            const SerdString* object_lang)
+{
+	FILE* const fd = writer->fd;
+	serd_write_node(writer, subject_type, subject, NULL, NULL);
+	fwrite(" ", 1, 1, fd);
+	serd_write_node(writer, predicate_type, predicate, NULL, NULL);
+	fwrite(" ", 1, 1, fd);
+	serd_write_node(writer, object_type, object, object_datatype, object_lang);
+	fwrite(" .\n", 1, 3, fd);
+	return true;
+}
+
+SERD_API
+SerdWriter
+serd_writer_new(SerdSyntax     syntax,
+                SerdNamespaces ns,
+                FILE*          file,
+                const SerdURI* base_uri)
+{
+	SerdWriter writer = malloc(sizeof(struct SerdWriterImpl));
+	writer->syntax   = syntax;
+	writer->ns       = ns;
+	writer->fd       = file;
+	writer->base_uri = *base_uri;
+	return writer;
+}
+
+SERD_API
+void
+serd_writer_set_base_uri(SerdWriter     writer,
+                         const SerdURI* uri)
+{
+	writer->base_uri = *uri;
+}
+
+SERD_API
+void
+serd_writer_free(SerdWriter writer)
+{
+	SerdWriter const me = (SerdWriter)writer;
+	free(me);
+}