Add SerdSink interface and hide implementations

7 files changed, 179 insertions, 81 deletions

diff --git a/src/n3.c b/src/n3.c
index 929b1a97..cd7e5a03 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -11,6 +11,7 @@
 
 #include "serd/node.h"
 #include "serd/reader.h"
+#include "serd/sink.h"
 #include "serd/statement.h"
 #include "serd/status.h"
 #include "serd/syntax.h"
@@ -1099,9 +1100,7 @@ read_anon(SerdReader* const reader,
       return r_err(reader, SERD_BAD_SYNTAX, "'.' inside blank\n");
     }
     read_ws_star(reader);
-    if (reader->end_func) {
-      reader->end_func(reader->handle, deref(reader, *dest));
-    }
+    serd_sink_write_end(reader->sink, deref(reader, *dest));
     *ctx.flags = old_flags;
   }
 
@@ -1453,9 +1452,7 @@ read_base(SerdReader* const reader, const bool sparql, const bool token)
 
   Ref uri = 0;
   TRY(st, read_IRIREF(reader, &uri));
-  if (reader->base_func) {
-    TRY(st, reader->base_func(reader->handle, deref(reader, uri)));
-  }
+  TRY(st, serd_sink_write_base(reader->sink, deref(reader, uri)));
   pop_node(reader, uri);
 
   read_ws_star(reader);
@@ -1491,10 +1488,8 @@ read_prefixID(SerdReader* const reader, const bool sparql, const bool token)
   Ref uri = 0;
   TRY(st, read_IRIREF(reader, &uri));
 
-  if (reader->prefix_func) {
-    st = reader->prefix_func(
-      reader->handle, deref(reader, name), deref(reader, uri));
-  }
+  st = serd_sink_write_prefix(
+    reader->sink, deref(reader, name), deref(reader, uri));
 
   pop_node(reader, uri);
   pop_node(reader, name);
@@ -1502,7 +1497,6 @@ read_prefixID(SerdReader* const reader, const bool sparql, const bool token)
     read_ws_star(reader);
     st = eat_byte_check(reader, '.') ? SERD_SUCCESS : SERD_BAD_SYNTAX;
   }
-
   return st;
 }
 
diff --git a/src/reader.c b/src/reader.c
index c7919ca6..284de45d 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -143,14 +143,12 @@ emit_statement(SerdReader* const reader, const ReadContext ctx, const Ref o)
     graph = reader->default_graph;
   }
 
-  const SerdStatus st = !reader->statement_func
-                          ? SERD_SUCCESS
-                          : reader->statement_func(reader->handle,
-                                                   *ctx.flags,
-                                                   graph,
-                                                   deref(reader, ctx.subject),
-                                                   deref(reader, ctx.predicate),
-                                                   deref(reader, o));
+  const SerdStatus st = serd_sink_write(reader->sink,
+                                        *ctx.flags,
+                                        deref(reader, ctx.subject),
+                                        deref(reader, ctx.predicate),
+                                        deref(reader, o),
+                                        graph);
 
   *ctx.flags &= SERD_ANON_CONT | SERD_LIST_CONT; // Preserve only cont flags
   return st;
@@ -164,26 +162,16 @@ read_doc(SerdReader* const reader)
 }
 
 SerdReader*
-serd_reader_new(const SerdSyntax syntax,
-                void* const      handle,
-                void (*const free_handle)(void*),
-                const SerdBaseFunc      base_func,
-                const SerdPrefixFunc    prefix_func,
-                const SerdStatementFunc statement_func,
-                const SerdEndFunc       end_func)
+serd_reader_new(const SerdSyntax syntax, const SerdSink* const sink)
 {
-  SerdReader* me     = (SerdReader*)calloc(1, sizeof(SerdReader));
-  me->handle         = handle;
-  me->free_handle    = free_handle;
-  me->base_func      = base_func;
-  me->prefix_func    = prefix_func;
-  me->statement_func = statement_func;
-  me->end_func       = end_func;
-  me->default_graph  = NULL;
-  me->stack          = serd_stack_new(SERD_PAGE_SIZE);
-  me->syntax         = syntax;
-  me->next_id        = 1;
-  me->strict         = true;
+  SerdReader* me = (SerdReader*)calloc(1, sizeof(SerdReader));
+
+  me->sink          = sink;
+  me->default_graph = NULL;
+  me->stack         = serd_stack_new(SERD_PAGE_SIZE);
+  me->syntax        = syntax;
+  me->next_id       = 1;
+  me->strict        = true;
 
   me->rdf_first = push_node(me, SERD_URI, NS_RDF "first", 48);
   me->rdf_rest  = push_node(me, SERD_URI, NS_RDF "rest", 47);
@@ -224,18 +212,9 @@ serd_reader_free(SerdReader* const reader)
 #endif
   free(reader->stack.buf);
   free(reader->bprefix);
-  if (reader->free_handle) {
-    reader->free_handle(reader->handle);
-  }
   free(reader);
 }
 
-void*
-serd_reader_handle(const SerdReader* const reader)
-{
-  return reader->handle;
-}
-
 void
 serd_reader_add_blank_prefix(SerdReader* const reader, const char* const prefix)
 {
diff --git a/src/reader.h b/src/reader.h
index 0de1df2a..db749fe8 100644
--- a/src/reader.h
+++ b/src/reader.h
@@ -45,27 +45,22 @@ typedef struct {
 } ReadContext;
 
 struct SerdReaderImpl {
-  void* handle;
-  void (*free_handle)(void* ptr);
-  SerdBaseFunc      base_func;
-  SerdPrefixFunc    prefix_func;
-  SerdStatementFunc statement_func;
-  SerdEndFunc       end_func;
-  SerdErrorFunc     error_func;
-  void*             error_handle;
-  Ref               rdf_first;
-  Ref               rdf_rest;
-  Ref               rdf_nil;
-  SerdNode*         default_graph;
-  SerdByteSource    source;
-  SerdStack         stack;
-  SerdSyntax        syntax;
-  unsigned          next_id;
-  uint8_t*          buf;
-  char*             bprefix;
-  size_t            bprefix_len;
-  bool              strict; ///< True iff strict parsing
-  bool              seen_genid;
+  const SerdSink* sink;
+  SerdErrorFunc   error_func;
+  void*           error_handle;
+  Ref             rdf_first;
+  Ref             rdf_rest;
+  Ref             rdf_nil;
+  SerdNode*       default_graph;
+  SerdByteSource  source;
+  SerdStack       stack;
+  SerdSyntax      syntax;
+  unsigned        next_id;
+  uint8_t*        buf;
+  char*           bprefix;
+  size_t          bprefix_len;
+  bool            strict; ///< True iff strict parsing
+  bool            seen_genid;
 #ifdef SERD_STACK_CHECK
   Ref*   allocs;   ///< Stack of push offsets
   size_t n_allocs; ///< Number of stack pushes
diff --git a/src/serdi.c b/src/serdi.c
index e3b41204..0de64b81 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -9,7 +9,6 @@
 #include "serd/error.h"
 #include "serd/node.h"
 #include "serd/reader.h"
-#include "serd/sink.h"
 #include "serd/status.h"
 #include "serd/stream.h"
 #include "serd/string_view.h"
@@ -348,13 +347,7 @@ main(int argc, char** argv)
     output_syntax, writer_flags, env, (SerdWriteFunc)fwrite, out_fd);
 
   SerdReader* const reader =
-    serd_reader_new(input_syntax,
-                    writer,
-                    NULL,
-                    (SerdBaseFunc)serd_writer_set_base_uri,
-                    (SerdPrefixFunc)serd_writer_set_prefix,
-                    (SerdStatementFunc)serd_writer_write_statement,
-                    (SerdEndFunc)serd_writer_end_anon);
+    serd_reader_new(input_syntax, serd_writer_sink(writer));
 
   serd_reader_set_strict(reader, !lax);
   if (quiet) {
diff --git a/src/sink.c b/src/sink.c
new file mode 100644
index 00000000..5e04ced6
--- /dev/null
+++ b/src/sink.c
@@ -0,0 +1,102 @@
+// Copyright 2011-2020 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#include "sink.h"
+
+#include "serd/node.h"
+#include "serd/sink.h"
+#include "serd/statement.h"
+#include "serd/status.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+SerdSink*
+serd_sink_new(void* handle, SerdFreeFunc free_handle)
+{
+  SerdSink* sink = (SerdSink*)calloc(1, sizeof(SerdSink));
+
+  sink->handle      = handle;
+  sink->free_handle = free_handle;
+
+  return sink;
+}
+
+void
+serd_sink_free(SerdSink* sink)
+{
+  if (sink) {
+    if (sink->free_handle) {
+      sink->free_handle(sink->handle);
+    }
+
+    free(sink);
+  }
+}
+
+SerdStatus
+serd_sink_set_base_func(SerdSink* sink, SerdBaseFunc base_func)
+{
+  sink->base = base_func;
+  return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_prefix_func(SerdSink* sink, SerdPrefixFunc prefix_func)
+{
+  sink->prefix = prefix_func;
+  return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_statement_func(SerdSink* sink, SerdStatementFunc statement_func)
+{
+  sink->statement = statement_func;
+  return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_set_end_func(SerdSink* sink, SerdEndFunc end_func)
+{
+  sink->end = end_func;
+  return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_write_base(const SerdSink* sink, const SerdNode* uri)
+{
+  return sink->base ? sink->base(sink->handle, uri) : SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_write_prefix(const SerdSink* sink,
+                       const SerdNode* name,
+                       const SerdNode* uri)
+{
+  return sink->prefix ? sink->prefix(sink->handle, name, uri) : SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_write(const SerdSink*          sink,
+                const SerdStatementFlags flags,
+                const SerdNode*          subject,
+                const SerdNode*          predicate,
+                const SerdNode*          object,
+                const SerdNode*          graph)
+{
+  assert(sink);
+  assert(subject);
+  assert(predicate);
+  assert(object);
+
+  return sink->statement
+           ? sink->statement(
+               sink->handle, flags, graph, subject, predicate, object)
+           : SERD_SUCCESS;
+}
+
+SerdStatus
+serd_sink_write_end(const SerdSink* sink, const SerdNode* 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..98884fe2
--- /dev/null
+++ b/src/sink.h
@@ -0,0 +1,21 @@
+// Copyright 2011-2020 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#ifndef SERD_SRC_SINK_H
+#define SERD_SRC_SINK_H
+
+#include "serd/sink.h"
+
+/**
+   An interface that receives a stream of RDF data.
+*/
+struct SerdSinkImpl {
+  void*             handle;
+  SerdFreeFunc      free_handle;
+  SerdBaseFunc      base;
+  SerdPrefixFunc    prefix;
+  SerdStatementFunc statement;
+  SerdEndFunc       end;
+};
+
+#endif // SERD_SRC_SINK_H
diff --git a/src/writer.c b/src/writer.c
index 01beb315..e674f2b1 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -5,6 +5,7 @@
 #include "env.h"
 #include "node.h"
 #include "serd_internal.h"
+#include "sink.h"
 #include "stack.h"
 #include "string_utils.h"
 #include "try.h"
@@ -15,6 +16,7 @@
 #include "serd/env.h"
 #include "serd/error.h"
 #include "serd/node.h"
+#include "serd/sink.h"
 #include "serd/statement.h"
 #include "serd/status.h"
 #include "serd/stream.h"
@@ -123,6 +125,7 @@ static const SepRule rules[] = {
 #undef SEP_EACH
 
 struct SerdWriterImpl {
+  SerdSink        iface;
   SerdSyntax      syntax;
   SerdWriterFlags flags;
   SerdEnv*        env;
@@ -143,6 +146,11 @@ typedef enum { WRITE_STRING, WRITE_LONG_STRING } TextContext;
 typedef enum { RESET_GRAPH = 1U << 0U, RESET_INDENT = 1U << 1U } ResetFlag;
 
 SERD_NODISCARD static SerdStatus
+serd_writer_set_prefix(SerdWriter*     writer,
+                       const SerdNode* name,
+                       const SerdNode* uri);
+
+SERD_NODISCARD static SerdStatus
 write_node(SerdWriter*        writer,
            const SerdNode*    node,
            Field              field,
@@ -951,7 +959,7 @@ terminate_context(SerdWriter* writer)
   return st;
 }
 
-SerdStatus
+static SerdStatus
 serd_writer_write_statement(SerdWriter* const        writer,
                             const SerdStatementFlags flags,
                             const SerdNode* const    graph,
@@ -1090,7 +1098,7 @@ serd_writer_write_statement(SerdWriter* const        writer,
   return st;
 }
 
-SerdStatus
+static SerdStatus
 serd_writer_end_anon(SerdWriter* writer, const SerdNode* node)
 {
   SerdStatus st = SERD_SUCCESS;
@@ -1146,6 +1154,12 @@ serd_writer_new(SerdSyntax      syntax,
   writer->byte_sink  = serd_byte_sink_new(
     ssink, stream, (flags & SERD_WRITE_BULK) ? SERD_PAGE_SIZE : 1);
 
+  writer->iface.handle    = writer;
+  writer->iface.base      = (SerdBaseFunc)serd_writer_set_base_uri;
+  writer->iface.prefix    = (SerdPrefixFunc)serd_writer_set_prefix;
+  writer->iface.statement = (SerdStatementFunc)serd_writer_write_statement;
+  writer->iface.end       = (SerdEndFunc)serd_writer_end_anon;
+
   return writer;
 }
 
@@ -1259,10 +1273,10 @@ serd_writer_free(SerdWriter* writer)
   free(writer);
 }
 
-SerdEnv*
-serd_writer_env(SerdWriter* writer)
+const SerdSink*
+serd_writer_sink(SerdWriter* writer)
 {
-  return writer->env;
+  return &writer->iface;
 }
 
 size_t