2 files changed, 20 insertions, 30 deletions

diff --git a/src/byte_source.c b/src/byte_source.c
index 6ba5a718..ccdc82e5 100644
--- a/src/byte_source.c
+++ b/src/byte_source.c
@@ -27,20 +27,23 @@
 SerdStatus
 serd_byte_source_page(SerdByteSource* source)
 {
-  source->read_head = 0;
+  uint8_t* const buf =
+    (source->page_size > 1 ? source->file_buf : &source->read_byte);
+
   const size_t n_read =
-    source->read_func(source->file_buf, 1, source->page_size, source->stream);
+    source->read_func(buf, 1, source->page_size, source->stream);
 
-  if (n_read == 0) {
-    source->file_buf[0] = '\0';
-    source->eof         = true;
-    return (source->error_func(source->stream) ? SERD_ERR_UNKNOWN
-                                               : SERD_FAILURE);
-  }
+  source->buf_size  = n_read;
+  source->read_head = 0;
+  source->eof       = false;
 
   if (n_read < source->page_size) {
-    source->file_buf[n_read] = '\0';
-    source->buf_size         = n_read;
+    buf[n_read] = '\0';
+    if (n_read == 0) {
+      source->eof = true;
+      return (source->error_func(source->stream) ? SERD_ERR_UNKNOWN
+                                                 : SERD_FAILURE);
+    }
   }
 
   return SERD_SUCCESS;
@@ -55,6 +58,7 @@ serd_byte_source_open_source(SerdByteSource*     source,
                              const SerdNode*     name,
                              size_t              page_size)
 {
+  assert(page_size > 0);
   memset(source, '\0', sizeof(*source));
   source->read_func   = read_func;
   source->error_func  = error_func;
@@ -99,6 +103,7 @@ serd_byte_source_open_string(SerdByteSource* source,
 {
   memset(source, '\0', sizeof(*source));
 
+  source->page_size = 1;
   source->name =
     name ? serd_node_copy(name) : serd_new_string(SERD_STATIC_STRING("string"));
 
diff --git a/src/byte_source.h b/src/byte_source.h
index db9b29af..ff281435 100644
--- a/src/byte_source.h
+++ b/src/byte_source.h
@@ -79,7 +79,8 @@ serd_byte_source_peek(SerdByteSource* source)
 static inline SerdStatus
 serd_byte_source_advance(SerdByteSource* source)
 {
-  SerdStatus st = SERD_SUCCESS;
+  SerdStatus st      = SERD_SUCCESS;
+  const bool was_eof = source->eof;
 
   switch (serd_byte_source_peek(source)) {
   case '\n':
@@ -90,28 +91,12 @@ serd_byte_source_advance(SerdByteSource* source)
     ++source->cur.col;
   }
 
-  const bool was_eof = source->eof;
   if (source->from_stream) {
-    source->eof = false;
-    if (source->page_size > 1) {
-      if (++source->read_head == source->page_size) {
-        st = serd_byte_source_page(source);
-      } else if (source->read_head == source->buf_size) {
-        source->eof = true;
-      }
-    } else {
-      source->eof = false;
-      if (!source->read_func(&source->read_byte, 1, 1, source->stream)) {
-        source->eof = true;
-        st =
-          source->error_func(source->stream) ? SERD_ERR_UNKNOWN : SERD_FAILURE;
-      }
+    if (++source->read_head >= source->buf_size) {
+      st = serd_byte_source_page(source);
     }
   } else if (!source->eof) {
-    ++source->read_head; // Move to next character in string
-    if (source->read_buf[source->read_head] == '\0') {
-      source->eof = true;
-    }
+    source->eof = source->read_buf[++source->read_head] == '\0';
   }
 
   return (was_eof && source->eof) ? SERD_FAILURE : st;