Simplify reader interface

6 files changed, 113 insertions, 139 deletions

diff --git a/serd/serd.h b/serd/serd.h
index 32dbe21e..89bce9cf 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -847,34 +847,26 @@ serd_reader_read_file(SerdReader* reader,
                       const char* uri);
 
 /**
-   Start an incremental read from a file handle.
+   Prepare to read from a stream.
 
-   Iff `bulk` is true, `file` will be read a page at a time.  This is more
-   efficient, but uses a page of memory and means that an entire page of input
-   must be ready before any callbacks will fire.  To react as soon as input
-   arrives, set `bulk` to false.
+   The `read_func` is guaranteed to only be called for `page_size` elements
+   with size 1 (i.e. `page_size` bytes).
 */
 SERD_API
 SerdStatus
-serd_reader_start_stream(SerdReader* reader,
-                         FILE*       file,
-                         const char* name,
-                         bool        bulk);
+serd_reader_start_stream(SerdReader*         reader,
+                         SerdSource          read_func,
+                         SerdStreamErrorFunc error_func,
+                         void*               stream,
+                         const char*         name,
+                         size_t              page_size);
 
 /**
-   Start an incremental read from a user-specified source.
-
-   The `read_func` is guaranteed to only be called for `page_size` elements
-   with size 1 (i.e. `page_size` bytes).
+   Prepare to read from a string.
 */
 SERD_API
 SerdStatus
-serd_reader_start_source_stream(SerdReader*         reader,
-                                SerdSource          read_func,
-                                SerdStreamErrorFunc error_func,
-                                void*               stream,
-                                const char*         name,
-                                size_t              page_size);
+serd_reader_start_string(SerdReader* reader, const char* utf8);
 
 /**
    Read a single "chunk" of data during an incremental read.
@@ -889,32 +881,22 @@ SerdStatus
 serd_reader_read_chunk(SerdReader* reader);
 
 /**
-   Finish an incremental read from a file handle.
-*/
-SERD_API
-SerdStatus
-serd_reader_end_stream(SerdReader* reader);
+   Read a complete document from the source.
 
-/**
-   Read `file`.
+   This function will continue pulling from the source until a complete
+   document has been read.  Note that this may block when used with streams,
+   for incremental reading use serd_reader_read_chunk().
 */
 SERD_API
 SerdStatus
-serd_reader_read_file_handle(SerdReader* reader,
-                             FILE*       file,
-                             const char* name);
+serd_reader_read_document(SerdReader* reader);
 
 /**
-   Read a user-specified byte source.
+   Finish reading from the source.
 */
 SERD_API
 SerdStatus
-serd_reader_read_source(SerdReader*         reader,
-                        SerdSource          source,
-                        SerdStreamErrorFunc error,
-                        void*               stream,
-                        const char*         name,
-                        size_t              page_size);
+serd_reader_end_stream(SerdReader* reader);
 
 /**
    Read `utf8`.
diff --git a/src/n3.c b/src/n3.c
index 9239f67c..b80660ab 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -1444,22 +1444,22 @@ skip_until(SerdReader* reader, uint8_t byte)
 	}
 }
 
-bool
+SerdStatus
 read_turtleTrigDoc(SerdReader* reader)
 {
 	while (!reader->source.eof) {
 		if (!read_n3_statement(reader)) {
 			if (reader->strict) {
-				return 0;
+				return SERD_ERR_UNKNOWN;
 			}
 			skip_until(reader, '\n');
 			reader->status = SERD_SUCCESS;
 		}
 	}
-	return reader->status <= SERD_FAILURE;
+	return reader->status;
 }
 
-bool
+SerdStatus
 read_nquadsDoc(SerdReader* reader)
 {
 	while (!reader->source.eof) {
@@ -1471,8 +1471,9 @@ read_nquadsDoc(SerdReader* reader)
 		if (peek_byte(reader) == EOF) {
 			break;
 		} else if (peek_byte(reader) == '@') {
-			return r_err(reader, SERD_ERR_BAD_SYNTAX,
-			             "syntax does not support directives\n");
+			r_err(reader, SERD_ERR_BAD_SYNTAX,
+			      "syntax does not support directives\n");
+			return SERD_ERR_BAD_SYNTAX;
 		}
 
 		// subject predicate object
@@ -1481,11 +1482,11 @@ read_nquadsDoc(SerdReader* reader)
 		    !(ctx.predicate = read_IRIREF(reader)) ||
 		    !read_ws_star(reader) ||
 		    !read_object(reader, &ctx, false, &ate_dot)) {
-			return false;
+			return SERD_ERR_UNKNOWN;
 		}
 
 		if (!ate_dot) {  // graphLabel?
-			TRY_RET(read_ws_star(reader));
+			read_ws_star(reader);
 			switch (peek_byte(reader)) {
 			case '.':
 				break;
@@ -1494,20 +1495,23 @@ read_nquadsDoc(SerdReader* reader)
 				break;
 			default:
 				if (!(ctx.graph = read_IRIREF(reader))) {
-					return false;
+					return SERD_ERR_UNKNOWN;
 				}
 			}
 
 			// Terminating '.'
-			TRY_RET(read_ws_star(reader));
+			read_ws_star(reader);
 			eat_byte_check(reader, '.');
 		}
 
-		TRY_RET(emit_statement(reader, ctx, ctx.object, ctx.datatype, ctx.lang));
+		if (!emit_statement(reader, ctx, ctx.object, ctx.datatype, ctx.lang)) {
+			break;
+		}
+
 		pop_node(reader, ctx.graph);
 		pop_node(reader, ctx.lang);
 		pop_node(reader, ctx.datatype);
 		pop_node(reader, ctx.object);
 	}
-	return reader->status <= SERD_FAILURE;
+	return reader->status;
 }
diff --git a/src/reader.c b/src/reader.c
index cbf40232..354618dc 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -25,6 +25,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+static SerdStatus serd_reader_prepare(SerdReader* reader);
+
 int
 r_err(SerdReader* reader, SerdStatus st, const char* fmt, ...)
 {
@@ -62,22 +64,6 @@ blank_id(SerdReader* reader)
 	return ref;
 }
 
-/** fread-like wrapper for getc (which is faster). */
-static size_t
-serd_file_read_byte(void* buf, size_t size, size_t nmemb, void* stream)
-{
-	(void)size;
-	(void)nmemb;
-
-	const int c = getc((FILE*)stream);
-	if (c == EOF) {
-		*((uint8_t*)buf) = 0;
-		return 0;
-	}
-	*((uint8_t*)buf) = (uint8_t)c;
-	return 1;
-}
-
 Ref
 push_node_padded(SerdReader* reader, size_t maxlen,
                  SerdType type, const char* str, size_t n_bytes)
@@ -153,9 +139,16 @@ read_statement(SerdReader* reader)
 	}
 }
 
-static bool
-read_doc(SerdReader* reader)
+SerdStatus
+serd_reader_read_document(SerdReader* reader)
 {
+	if (!reader->source.prepared) {
+		SerdStatus st = serd_reader_prepare(reader);
+		if (st) {
+			return st;
+		}
+	}
+
 	return ((reader->syntax == SERD_NQUADS) ? read_nquadsDoc(reader)
 	                                        : read_turtleTrigDoc(reader));
 }
@@ -266,10 +259,20 @@ serd_reader_read_file(SerdReader* reader,
 		return SERD_ERR_UNKNOWN;
 	}
 
-	SerdStatus ret = serd_reader_read_file_handle(reader, fd, path);
+	SerdStatus st = serd_reader_start_stream(
+		reader, (SerdSource)fread, (SerdStreamErrorFunc)ferror,
+		fd, path, SERD_PAGE_SIZE);
+
+	if (!st) {
+		st = serd_reader_read_document(reader);
+	}
+
+	const SerdStatus est = serd_reader_end_stream(reader);
+
 	fclose(fd);
 	free(path);
-	return ret;
+
+	return st ? st : est;
 }
 
 static SerdStatus
@@ -290,30 +293,21 @@ skip_bom(SerdReader* me)
 }
 
 SerdStatus
-serd_reader_start_stream(SerdReader* reader,
-                         FILE*       file,
-                         const char* name,
-                         bool        bulk)
+serd_reader_start_stream(SerdReader*         reader,
+                         SerdSource          read_func,
+                         SerdStreamErrorFunc error_func,
+                         void*               stream,
+                         const char*         name,
+                         size_t              page_size)
 {
-	return serd_reader_start_source_stream(
-		reader,
-		bulk ? (SerdSource)fread : serd_file_read_byte,
-		(SerdStreamErrorFunc)ferror,
-		file,
-		name,
-		bulk ? SERD_PAGE_SIZE : 1);
+	return serd_byte_source_open_source(
+		&reader->source, read_func, error_func, stream, name, page_size);
 }
 
 SerdStatus
-serd_reader_start_source_stream(SerdReader*         reader,
-                                SerdSource          read_func,
-                                SerdStreamErrorFunc error_func,
-                                void*               stream,
-                                const char*         name,
-                                size_t              page_size)
+serd_reader_start_string(SerdReader* reader, const char* utf8)
 {
-	return serd_byte_source_open_source(
-		&reader->source, read_func, error_func, stream, name, page_size);
+	return serd_byte_source_open_string(&reader->source, utf8);
 }
 
 static SerdStatus
@@ -355,48 +349,12 @@ serd_reader_end_stream(SerdReader* reader)
 }
 
 SerdStatus
-serd_reader_read_file_handle(SerdReader* reader,
-                             FILE*       file,
-                             const char* name)
-{
-	return serd_reader_read_source(
-		reader, (SerdSource)fread, (SerdStreamErrorFunc)ferror,
-		file, name, SERD_PAGE_SIZE);
-}
-
-SerdStatus
-serd_reader_read_source(SerdReader*         reader,
-                        SerdSource          source,
-                        SerdStreamErrorFunc error,
-                        void*               stream,
-                        const char*         name,
-                        size_t              page_size)
-{
-	SerdStatus st = serd_reader_start_source_stream(
-		reader, source, error, stream, name, page_size);
-
-	if (st || (st = serd_reader_prepare(reader))) {
-		serd_reader_end_stream(reader);
-		return st;
-	} else if (!read_doc(reader)) {
-		serd_reader_end_stream(reader);
-		return SERD_ERR_UNKNOWN;
-	}
-
-	return serd_reader_end_stream(reader);
-}
-
-SerdStatus
 serd_reader_read_string(SerdReader* reader, const char* utf8)
 {
-	serd_byte_source_open_string(&reader->source, utf8);
-
-	SerdStatus st = serd_reader_prepare(reader);
-	if (!st) {
-		st = read_doc(reader) ? SERD_SUCCESS : SERD_ERR_UNKNOWN;
-	}
+	serd_reader_start_string(reader, utf8);
 
-	serd_byte_source_close(&reader->source);
+	const SerdStatus st  = serd_reader_read_document(reader);
+	const SerdStatus est = serd_byte_source_close(&reader->source);
 
-	return st;
+	return st ? st : est;
 }
diff --git a/src/serd_internal.h b/src/serd_internal.h
index 7d06c2e1..fd5aca5e 100644
--- a/src/serd_internal.h
+++ b/src/serd_internal.h
@@ -633,8 +633,8 @@ Ref pop_node(SerdReader* reader, Ref ref);
 bool emit_statement(SerdReader* reader, ReadContext ctx, Ref o, Ref d, Ref l);
 
 bool read_n3_statement(SerdReader* reader);
-bool read_nquadsDoc(SerdReader* reader);
-bool read_turtleTrigDoc(SerdReader* reader);
+SerdStatus read_nquadsDoc(SerdReader* reader);
+SerdStatus read_turtleTrigDoc(SerdReader* reader);
 
 typedef enum {
 	FIELD_NONE,
diff --git a/src/serdi.c b/src/serdi.c
index a631aebf..98ef99c8 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -120,6 +120,22 @@ quiet_error_sink(void* handle, const SerdError* e)
 	return SERD_SUCCESS;
 }
 
+/** fread-like wrapper for getc (which is faster). */
+static size_t
+serd_file_read_byte(void* buf, size_t size, size_t nmemb, void* stream)
+{
+	(void)size;
+	(void)nmemb;
+
+	const int c = getc((FILE*)stream);
+	if (c == EOF) {
+		*((uint8_t*)buf) = 0;
+		return 0;
+	}
+	*((uint8_t*)buf) = (uint8_t)c;
+	return 1;
+}
+
 int
 main(int argc, char** argv)
 {
@@ -294,17 +310,21 @@ main(int argc, char** argv)
 
 	SerdStatus status = SERD_SUCCESS;
 	if (!from_file) {
-		status = serd_reader_read_string(reader, input);
-	} else if (bulk_read) {
-		status = serd_reader_read_file_handle(reader, in_fd, in_name);
+		status = serd_reader_start_string(reader, input);
 	} else {
-		status = serd_reader_start_stream(reader, in_fd, in_name, false);
-		while (!status) {
-			status = serd_reader_read_chunk(reader);
-		}
-		serd_reader_end_stream(reader);
+		status = serd_reader_start_stream(
+			reader,
+			bulk_read ? (SerdSource)fread : serd_file_read_byte,
+			(SerdStreamErrorFunc)ferror,
+			in_fd,
+			in_name,
+			bulk_read ? SERD_PAGE_SIZE : 1);
 	}
 
+	status = serd_reader_read_document(reader);
+
+	serd_reader_end_stream(reader);
+
 	serd_reader_free(reader);
 	serd_writer_finish(writer);
 	serd_writer_free(writer);
diff --git a/tests/serd_test.c b/tests/serd_test.c
index c15f45d3..9b3cc2d8 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -122,7 +122,12 @@ test_read_chunks(void)
 	assert(serd_reader_get_handle(reader) == rt);
 	assert(f);
 
-	SerdStatus st = serd_reader_start_stream(reader, f, NULL, false);
+	SerdStatus st = serd_reader_start_stream(reader,
+	                                         (SerdSource)fread,
+	                                         (SerdStreamErrorFunc)ferror,
+	                                         f,
+	                                         NULL,
+	                                         1);
 	assert(st == SERD_SUCCESS);
 
 	// Write two statement separated by null characters
@@ -158,11 +163,16 @@ test_read_chunks(void)
 	assert(st == SERD_SUCCESS); // FIXME: return SERD_FAILURE?
 	assert(rt->n_statements == 2);
 
-	// EOF
+	// FIXME: Successful read of nothing
 	st = serd_reader_read_chunk(reader);
 	assert(st == SERD_SUCCESS); // FIXME: return SERD_FAILURE?
 	assert(rt->n_statements == 2);
 
+	// EOF
+	st = serd_reader_read_chunk(reader);
+	assert(st == SERD_FAILURE);
+	assert(rt->n_statements == 2);
+
 	serd_reader_free(reader);
 	fclose(f);
 }