Mercurial > hg > ucx / file diff

--- a/src/buffer.c	Wed May 09 15:04:15 2018 +0200
+++ b/src/buffer.c	Wed May 09 20:15:10 2018 +0200
@@ -237,6 +237,61 @@
     }
 }
 
-size_t ucx_buffer_puts(UcxBuffer *buffer, char *str) {
+size_t ucx_buffer_puts(UcxBuffer *buffer, const char *str) {
     return ucx_buffer_write((const void*)str, 1, strlen(str), buffer);
 }
+
+int ucx_buffer_shift_left(UcxBuffer* buffer, size_t shift) {
+    if (shift >= buffer->size) {
+        buffer->pos = buffer->size = 0;
+    } else {
+        memmove(buffer->space, buffer->space + shift, buffer->size - shift);
+        buffer->size -= shift;
+        
+        if (buffer->pos >= shift) {
+            buffer->pos -= shift;
+        } else {
+            buffer->pos = 0;
+        }
+    }
+    return 0;
+}
+
+int ucx_buffer_shift_right(UcxBuffer* buffer, size_t shift) {
+    size_t req_capacity = buffer->size + shift;
+    size_t movebytes;
+    
+    // auto extend buffer, if required and enabled
+    if (buffer->capacity < req_capacity) {
+        if ((buffer->flags & UCX_BUFFER_AUTOEXTEND) == UCX_BUFFER_AUTOEXTEND) {
+            if (ucx_buffer_extend(buffer, req_capacity - buffer->capacity)) {
+                return 1;
+            }
+            movebytes = buffer->size;
+        } else {
+            movebytes = buffer->capacity - shift;
+        }
+    } else {
+        movebytes = buffer->size;
+    }
+    
+    memmove(buffer->space + shift, buffer->space, movebytes);
+    buffer->size = shift+movebytes;
+    
+    buffer->pos += shift;
+    if (buffer->pos > buffer->size) {
+        buffer->pos = buffer->size;
+    }
+    
+    return 0;
+}
+
+int ucx_buffer_shift(UcxBuffer* buffer, off_t shift) {
+    if (shift < 0) {
+        return ucx_buffer_shift_left(buffer, (size_t) (-shift));
+    } else if (shift > 0) {
+        return ucx_buffer_shift_right(buffer, (size_t) shift);
+    } else {
+        return 0;
+    }
+}