fpi-byte-reader: Add support to read to a static buffer

This works through macros when the size of a buffer is statically
defined

doc/libfprint-2-sections.txt

@@ -198,6 +198,8 @@ fpi_byte_reader_get_float64_be
 fpi_byte_reader_peek_float64_be
 fpi_byte_reader_get_data
 fpi_byte_reader_peek_data
+fpi_byte_reader_get_data_static
+fpi_byte_reader_peek_data_static
 fpi_byte_reader_dup_data
 fpi_byte_reader_masked_scan_uint32
 fpi_byte_reader_masked_scan_uint32_peek

libfprint/fpi-byte-reader.c

@@ -848,6 +848,41 @@ fpi_byte_reader_peek_data (const FpiByteReader * reader, guint size,
   return fpi_byte_reader_peek_data_inline (reader, size, val);
 }
 
+/**
+ * fpi_byte_reader_get_data_fixed:
+ * @reader: a #FpiByteReader instance
+ * @size: Size in bytes
+ * @val: (out) (array length=size): address of a buffer to copy data into
+ *
+ * Copies @size bytes from the current data position into @val if at
+ * least @size bytes are left, and updates the current position.
+ *
+ * Returns: %TRUE if successful, %FALSE otherwise.
+ */
+gboolean
+(fpi_byte_reader_get_data_static) (FpiByteReader * reader, guint size,
+    const guint8 * val)
+{
+  return (fpi_byte_reader_get_data_inline_static) (reader, size, val);
+}
+
+/**
+ * fpi_byte_reader_peek_data_fixed:
+ * @reader: a #FpiByteReader instance
+ * @size: Size in bytes
+ * @val: (out) (array length=size): address of a buffer to copy data into
+ *
+ * Like fpi_byte_reader_get_data_fixed() but does not advance the position.
+ *
+ * Returns: %TRUE if successful, %FALSE otherwise.
+ */
+gboolean
+(fpi_byte_reader_peek_data_static) (const FpiByteReader * reader, guint size,
+    guint8 * val)
+{
+  return (fpi_byte_reader_peek_data_inline_static) (reader, size, val);
+}
+
 /**
  * fpi_byte_reader_dup_data:
  * @reader: a #FpiByteReader instance

libfprint/fpi-byte-reader.h

@@ -222,9 +222,15 @@ gboolean        fpi_byte_reader_dup_data        (FpiByteReader * reader, guint s
 gboolean        fpi_byte_reader_get_data        (FpiByteReader * reader, guint size, const guint8 ** val);
 
 
+gboolean        fpi_byte_reader_get_data_static (FpiByteReader * reader, guint size, const guint8  * val);
+
+
 gboolean        fpi_byte_reader_peek_data       (const FpiByteReader * reader, guint size, const guint8 ** val);
 
 
+gboolean        fpi_byte_reader_peek_data_static (const FpiByteReader * reader, guint size, guint8   * val);
+
+
 GBytes *        fpi_byte_reader_get_bytes       (FpiByteReader *reader, guint size);
 
 
@@ -681,6 +687,32 @@ fpi_byte_reader_get_bytes_inline (FpiByteReader *reader, guint size)
   return g_bytes_new_static (data, size);
 }
 
+static inline gboolean
+(fpi_byte_reader_get_data_inline_static) (FpiByteReader * reader, guint size, const guint8 * val)
+{
+  g_return_val_if_fail (reader != NULL, FALSE);
+  g_return_val_if_fail (val != NULL, FALSE);
+
+  if (G_UNLIKELY (size > reader->size || fpi_byte_reader_get_remaining_unchecked (reader) < size))
+    return FALSE;
+
+  memcpy ((void *) val, fpi_byte_reader_get_data_unchecked (reader, size), size);
+  return TRUE;
+}
+
+static inline gboolean
+(fpi_byte_reader_peek_data_inline_static) (const FpiByteReader * reader, guint size, guint8 * val)
+{
+  g_return_val_if_fail (reader != NULL, FALSE);
+  g_return_val_if_fail (val != NULL, FALSE);
+
+  if (G_UNLIKELY (size > reader->size || fpi_byte_reader_get_remaining_unchecked (reader) < size))
+    return FALSE;
+
+  memcpy (val, fpi_byte_reader_peek_data_unchecked (reader), size);
+  return TRUE;
+}
+
 static inline guint
 fpi_byte_reader_get_pos_inline (const FpiByteReader * reader)
 {
@@ -716,6 +748,31 @@ fpi_byte_reader_skip_inline (FpiByteReader * reader, guint nbytes)
 #define fpi_byte_reader_peek_bytes(reader,size) \
     fpi_byte_reader_peek_bytes_inline(reader,size)
 
+/**
+ * fpi_byte_reader_get_data_static:
+ * @reader: a #FpiByteReader
+ * @val: fixed-size array (e.g. `uint8_t buf[32]`)
+ *
+ * Reads @size bytes from @reader directly into @val, where @size is
+ * deduced via `sizeof()` - only safe with true C arrays.
+ *
+ * Returns: %TRUE on success, %FALSE otherwise.
+ */
+#define fpi_byte_reader_get_data_static(reader,val) \
+    (fpi_byte_reader_get_data_static) (reader,sizeof(val),val)
+
+/**
+ * fpi_byte_reader_peek_data_static:
+ * @reader: a #FpiByteReader
+ * @val: fixed-size array (e.g. `uint8_t buf[32]`)
+ *
+ * Like fpi_byte_reader_get_data_static() but does not advance the position.
+ *
+ * Returns: %TRUE on success, %FALSE otherwise.
+ */
+#define fpi_byte_reader_peek_data_static(reader,val) \
+    (fpi_byte_reader_peek_data_static) (reader,sizeof(val),val)
+
 #endif /* FPI_BYTE_READER_DISABLE_INLINES */
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (FpiByteReader, fpi_byte_reader_free);