1 files changed, 85 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-iotools/helpers.go b/vendor/codeberg.org/gruf/go-iotools/helpers.go
new file mode 100644
index 000000000..0e50e05e0
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-iotools/helpers.go
@@ -0,0 +1,85 @@
+package iotools
+
+import "io"
+
+// AtEOF returns true when reader at EOF,
+// this is checked with a 0 length read.
+func AtEOF(r io.Reader) bool {
+	_, err := r.Read(nil)
+	return (err == io.EOF)
+}
+
+// GetReadCloserLimit attempts to cast io.Reader to access its io.LimitedReader with limit.
+func GetReaderLimit(r io.Reader) (*io.LimitedReader, int64) {
+	lr, ok := r.(*io.LimitedReader)
+	if !ok {
+		return nil, -1
+	}
+	return lr, lr.N
+}
+
+// UpdateReaderLimit attempts to  update the limit of a reader for existing, newly wrapping if necessary.
+func UpdateReaderLimit(r io.Reader, limit int64) (*io.LimitedReader, int64) {
+	lr, ok := r.(*io.LimitedReader)
+	if !ok {
+		lr = &io.LimitedReader{r, limit}
+		return lr, limit
+	}
+
+	if limit < lr.N {
+		// Update existing.
+		lr.N = limit
+	}
+
+	return lr, lr.N
+}
+
+// GetReadCloserLimit attempts to unwrap io.ReadCloser to access its io.LimitedReader with limit.
+func GetReadCloserLimit(rc io.ReadCloser) (*io.LimitedReader, int64) {
+	rct, ok := rc.(*ReadCloserType)
+	if !ok {
+		return nil, -1
+	}
+	lr, ok := rct.Reader.(*io.LimitedReader)
+	if !ok {
+		return nil, -1
+	}
+	return lr, lr.N
+}
+
+// UpdateReadCloserLimit attempts to update the limit of a readcloser for existing, newly wrapping if necessary.
+func UpdateReadCloserLimit(rc io.ReadCloser, limit int64) (io.ReadCloser, *io.LimitedReader, int64) {
+
+	// Check for our wrapped ReadCloserType.
+	if rct, ok := rc.(*ReadCloserType); ok {
+
+		// Attempt to update existing wrapped limit reader.
+		if lr, ok := rct.Reader.(*io.LimitedReader); ok {
+
+			if limit < lr.N {
+				// Update existing.
+				lr.N = limit
+			}
+
+			return rct, lr, lr.N
+		}
+
+		// Wrap the reader type with new limit.
+		lr := &io.LimitedReader{rct.Reader, limit}
+		rct.Reader = lr
+
+		return rct, lr, lr.N
+	}
+
+	// Wrap separated types.
+	rct := &ReadCloserType{
+		Reader: rc,
+		Closer: rc,
+	}
+
+	// Wrap separated reader part with limit.
+	lr := &io.LimitedReader{rct.Reader, limit}
+	rct.Reader = lr
+
+	return rct, lr, lr.N
+}