Add overloads for GetBuffer(..) and SetBuffer(..) that take an explic…

…it offset and length. (#394)
libplctag · Jul 11, 2024 · c18df56 · c18df56
1 parent 66e12d8
commit c18df56
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Showing 2 changed files with 25 additions and 3 deletions.
diff --git a/src/libplctag/NativeTagWrapper.cs b/src/libplctag/NativeTagWrapper.cs
@@ -531,9 +531,14 @@ public Status GetStatus()
         }
 
         public void GetBuffer(byte[] buffer)
+        {
+            GetBuffer(0, buffer, buffer.Length);
+        }
+
+        public void GetBuffer(int offset, byte[] buffer, int length)
         {
             ThrowIfAlreadyDisposed();
-            var result = (Status)_native.plc_tag_get_raw_bytes(nativeTagHandle, 0, buffer, buffer.Length);
+            var result = (Status)_native.plc_tag_get_raw_bytes(nativeTagHandle, offset, buffer, length);
             ThrowIfStatusNotOk(result);
         }
 
@@ -551,14 +556,21 @@ public byte[] GetBuffer()
         }
 
         public void SetBuffer(byte[] buffer)
+        {
+            SetBuffer(0, buffer, buffer.Length);
+        }
+
+        public void SetBuffer(int start_offset, byte[] buffer, int length)
         {
             ThrowIfAlreadyDisposed();
 
             GetNativeValueAndThrowOnNegativeResult(_native.plc_tag_set_size, buffer.Length);
-            var result = (Status)_native.plc_tag_set_raw_bytes(nativeTagHandle, 0, buffer, buffer.Length);
+            var result = (Status)_native.plc_tag_set_raw_bytes(nativeTagHandle, start_offset, buffer, length);
             ThrowIfStatusNotOk(result);
         }
 
+
+
         private int GetIntAttribute(string attributeName)
         {
             var result = _native.plc_tag_get_int_attribute(nativeTagHandle, attributeName, int.MinValue);

diff --git a/src/libplctag/Tag.cs b/src/libplctag/Tag.cs
@@ -418,7 +418,17 @@ public uint? MaxRequestsInFlight
         /// Use this instead of <see cref="GetBuffer()"/> to avoid creating a new block of memory.
         /// </remarks>
         public void GetBuffer(byte[] buffer)                => _tag.GetBuffer(buffer);
-        public void SetBuffer(byte[] newBuffer)             => _tag.SetBuffer(newBuffer);
+
+        /// <summary>
+        /// Fills the supplied buffer with the raw, unprocessed bytes from the tag buffer.
+        /// </summary>
+        /// <remarks>
+        /// Use this instead of <see cref="GetBuffer()"/> to avoid creating a new block of memory.
+        /// </remarks>
+        public void GetBuffer(int offset, byte[] buffer, int length)    => _tag.GetBuffer(offset, buffer, length);
+
+        public void SetBuffer(byte[] newBuffer)                         => _tag.SetBuffer(newBuffer);
+        public void SetBuffer(int offset, byte[] buffer, int length)    => _tag.SetBuffer(offset, buffer, length);
 
         /// <summary>
         /// This function retrieves an attribute of the raw tag byte array.