Mercurial > hg > ucx / file diff

--- a/src/buffer.c	Tue Nov 25 20:35:27 2025 +0100
+++ b/src/buffer.c	Wed Nov 26 23:06:12 2025 +0100
@@ -192,6 +192,35 @@
 
 }
 
+size_t cxBufferPop(CxBuffer *buffer, size_t size, size_t nitems) {
+    size_t len;
+    if (cx_szmul(size, nitems, &len)) {
+        // LCOV_EXCL_START
+        errno = EOVERFLOW;
+        return 0;
+        // LCOV_EXCL_STOP
+    }
+    if (len == 0) return 0;
+    if (len > buffer->size) {
+        if (size == 1) {
+            // simple case: everything can be discarded
+            len = buffer->size;
+        } else {
+            // complicated case: misaligned bytes must stay
+            size_t misalignment = buffer->size % size;
+            len = buffer->size - misalignment;
+        }
+    }
+    buffer->size -= len;
+
+    // adjust position, if required
+    if (buffer->pos > buffer->size) {
+        buffer->pos = buffer->size;
+    }
+
+    return len / size;
+}
+
 void cxBufferClear(CxBuffer *buffer) {
     if (0 == (buffer->flags & CX_BUFFER_COPY_ON_WRITE)) {
         memset(buffer->bytes, 0, buffer->size);