Add serd_world_get_blank()

5 files changed, 86 insertions, 2 deletions

diff --git a/include/serd/serd.h b/include/serd/serd.h
index a04f1c8f..3be32a65 100644
--- a/include/serd/serd.h
+++ b/include/serd/serd.h
@@ -869,6 +869,16 @@ void
 serd_world_free(SerdWorld* SERD_NULLABLE world);
 
 /**
+   Return a unique blank node.
+
+   The returned node is valid only until the next time serd_world_get_blank()
+   is called or the world is destroyed.
+*/
+SERD_API
+const SerdNode* SERD_NONNULL
+serd_world_get_blank(SerdWorld* SERD_NONNULL world);
+
+/**
    Set a function to be called when errors occur.
 
    The `error_func` will be called with `handle` as its first argument.  If
diff --git a/src/world.c b/src/world.c
index e14a04c9..4413f433 100644
--- a/src/world.c
+++ b/src/world.c
@@ -16,6 +16,7 @@
 
 #include "world.h"
 
+#include "node.h"
 #include "serd_config.h"
 #include "system.h"
 
@@ -27,6 +28,9 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
+#define BLANK_CHARS 12
 
 FILE*
 serd_world_fopen(SerdWorld* world, const char* path, const char* mode)
@@ -81,13 +85,32 @@ serd_world_errorf(const SerdWorld* const world,
 SerdWorld*
 serd_world_new(void)
 {
-  return (SerdWorld*)calloc(1, sizeof(SerdWorld));
+  SerdWorld* world = (SerdWorld*)calloc(1, sizeof(SerdWorld));
+
+  world->blank_node = serd_new_blank(SERD_STRING("b00000000000"));
+
+  return world;
 }
 
 void
 serd_world_free(SerdWorld* const world)
 {
-  free(world);
+  if (world) {
+    serd_node_free(world->blank_node);
+    free(world);
+  }
+}
+
+const SerdNode*
+serd_world_get_blank(SerdWorld* const world)
+{
+  char* buf = serd_node_buffer(world->blank_node);
+  memset(buf, 0, BLANK_CHARS + 1);
+
+  world->blank_node->length =
+    (size_t)snprintf(buf, BLANK_CHARS + 1, "b%u", ++world->next_blank_id);
+
+  return world->blank_node;
 }
 
 void
diff --git a/src/world.h b/src/world.h
index ab7aad80..99f0c92d 100644
--- a/src/world.h
+++ b/src/world.h
@@ -19,11 +19,14 @@
 
 #include "serd/serd.h"
 
+#include <stdint.h>
 #include <stdio.h>
 
 struct SerdWorldImpl {
   SerdErrorFunc error_func;
   void*         error_handle;
+  uint32_t      next_blank_id;
+  SerdNode*     blank_node;
 };
 
 /// Open a file configured for fast sequential reading
diff --git a/test/meson.build b/test/meson.build
index 978bc779..05701f42 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -14,6 +14,7 @@ unit_tests = [
   'sink',
   'string',
   'uri',
+  'world',
   'writer',
 ]
 
diff --git a/test/test_world.c b/test/test_world.c
new file mode 100644
index 00000000..a7728037
--- /dev/null
+++ b/test/test_world.c
@@ -0,0 +1,47 @@
+/*
+  Copyright 2011-2020 David Robillard <d@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.
+*/
+
+#undef NDEBUG
+
+#include "serd/serd.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+static void
+test_get_blank(void)
+{
+  SerdWorld* world = serd_world_new();
+  char       expected[12];
+
+  for (unsigned i = 0; i < 32; ++i) {
+    const SerdNode* blank = serd_world_get_blank(world);
+
+    snprintf(expected, sizeof(expected), "b%u", i + 1);
+    assert(!strcmp(serd_node_string(blank), expected));
+  }
+
+  serd_world_free(world);
+}
+
+int
+main(void)
+{
+  test_get_blank();
+
+  return 0;
+}