snapshot before regression test

includes/viperio.py

@@ -0,0 +1,57 @@
+import t, c
+from stdint import *
+
+
+class Buf:
+    data: t.CChar | t.CPtr
+    length: t.CSizeT
+    capacity: t.CSizeT
+    owned: bool
+
+    def __init__(self, data: t.CChar | t.CPtr, capacity: t.CSizeT, length: t.CSizeT = 0, owned: bool = False):
+        self.data = data
+        self.capacity = capacity
+        self.length = length
+        self.owned = owned
+
+    def clear(self):
+        self.length = 0
+        if self.data != None and self.capacity > 0:
+            self.data[0] = 0
+
+    def write(self, src: t.CChar | t.CPtr, count: t.CSizeT) -> t.CSizeT:
+        if self.data == None: return 0
+        if src == None: return 0
+        if count == 0: return 0
+        avail: t.CSizeT = self.capacity - self.length
+        if avail <= 0: return 0
+        n: t.CSizeT = count if count < avail else avail
+        i: t.CSizeT = 0
+        while i < n:
+            self.data[self.length + i] = src[i]
+            i += 1
+        self.length += n
+        self.data[self.length] = 0
+        return n
+
+    def cstr(self) -> t.CChar | t.CPtr:
+        return self.data
+
+    def reset(self):
+        self.length = 0
+        if self.data != None and self.capacity > 0:
+            self.data[0] = 0
+
+    def __enter__(self) -> 'Buf' | t.CPtr:
+        return self
+
+    def __exit__(self):
+        self.reset()
+
+    def free(self):
+        if self.owned and self.data != None:
+            self.data[0] = 0
+            self.owned = False
+        self.data = None
+        self.length = 0
+        self.capacity = 0