Factor out file reading from reader

1 files changed, 107 insertions, 0 deletions

diff --git a/src/byte_source.c b/src/byte_source.c
new file mode 100644
index 00000000..e5bb47cf
--- /dev/null
+++ b/src/byte_source.c
@@ -0,0 +1,107 @@
+/*
+  Copyright 2011-2017 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.
+*/
+
+#include "serd_internal.h"
+
+static inline SerdStatus
+serd_byte_source_page(SerdByteSource* source)
+{
+	source->read_head = 0;
+	size_t n_read = source->read_func(
+		source->file_buf, 1, SERD_PAGE_SIZE, source->stream);
+	if (n_read == 0) {
+		source->file_buf[0] = '\0';
+		return (source->error_func(source->stream)
+		        ? SERD_ERR_UNKNOWN : SERD_FAILURE);
+	} else if (n_read < SERD_PAGE_SIZE) {
+		source->file_buf[n_read] = '\0';
+	}
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_byte_source_open_source(SerdByteSource*     source,
+                             SerdSource          read_func,
+                             SerdStreamErrorFunc error_func,
+                             void*               stream,
+                             bool                bulk)
+{
+	memset(source, '\0', sizeof(*source));
+	source->stream      = stream;
+	source->from_stream = true;
+	source->paging      = bulk;
+	source->error_func  = error_func;
+	source->read_func   = read_func;
+
+	if (bulk) {
+		source->file_buf = (uint8_t*)serd_bufalloc(SERD_PAGE_SIZE);
+		source->read_buf = source->file_buf;
+		memset(source->file_buf, '\0', SERD_PAGE_SIZE);
+	} else {
+		source->read_buf = &source->read_byte;
+	}
+
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_byte_source_prepare(SerdByteSource* source)
+{
+	if (!source->prepared) {
+		source->prepared = true;
+		if (source->paging) {
+			return serd_byte_source_page(source);
+		} else if (source->from_stream) {
+			return serd_byte_source_advance(source);
+		}
+	}
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_byte_source_open_string(SerdByteSource* source, const uint8_t* utf8)
+{
+	memset(source, '\0', sizeof(*source));
+	source->read_buf = utf8;
+	source->prepared = true;
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_byte_source_close(SerdByteSource* source)
+{
+	if (source->paging) {
+		free(source->file_buf);
+	}
+	memset(source, '\0', sizeof(*source));
+	return SERD_SUCCESS;
+}
+
+SerdStatus
+serd_byte_source_advance(SerdByteSource* source)
+{
+	SerdStatus st = SERD_SUCCESS;
+	if (source->from_stream && !source->paging) {
+		if (source->read_func(&source->read_byte, 1, 1, source->stream) == 0) {
+			return (source->error_func(source->stream)
+			        ? SERD_ERR_UNKNOWN : SERD_FAILURE);
+		}
+	} else if (++source->read_head == SERD_PAGE_SIZE && source->paging) {
+		st = serd_byte_source_page(source);
+	}
+
+	return st;
+}