io::read_fully now handles unbounded streams properly

lib/std/io/stream.c3

@@ -1,7 +1,5 @@
 module std::io;
 import std::math;
-import std::core::env;
-
 
 interface InStream
 {
@@ -36,7 +34,7 @@ fn usz? available(InStream s)
 		s.seek(curr, Seek.SET)!;
 		return len - curr;
 	}
-	return 0;
+	return ^io::UNSUPPORTED_OPERATION;
 }
 
 macro bool @is_instream(#expr) @const
@@ -90,21 +88,31 @@ macro usz? read_all(stream, char[] buffer)
 }
 
 <*
+ This function will read to the end of the stream.
+
  @require @is_instream(stream)
 *>
 macro char[]? read_fully(Allocator allocator, stream)
 {
-	usz len = available(stream)!;
-	char* data = allocator::malloc_try(allocator, len)!;
-	defer catch allocator::free(allocator, data);
-	usz read = 0;
-	while (read < len)
+	// Efficient path if it is possible to pre-allocate
+	if (try len = available(stream))
 	{
-		read += stream.read(data[read:len - read])!;
+		char* data = allocator::malloc_try(allocator, len)!;
+		defer catch allocator::free(allocator, data);
+		usz read = 0;
+		while (read < len)
+		{
+			read += stream.read(data[read:len - read])!;
+		}
+		return data[:len];
 	}
-	return data[:len];
+	ByteWriter writer;
+	writer.init(allocator);
+	copy_to(stream, &writer)!;
+	return writer.array_view();
 }
 
+
 <*
  @require @is_outstream(stream)
 *>

lib/std/io/stream/bytewriter.c3

@@ -43,6 +43,11 @@ fn void? ByteWriter.destroy(&self) @dynamic
 	*self = { };
 }
 
+fn char[] ByteWriter.array_view(self) @inline
+{
+	return self.bytes[:self.index];
+}
+
 fn String ByteWriter.str_view(&self) @inline
 {
 	return (String)self.bytes[:self.index];
@@ -91,7 +96,7 @@ fn usz? ByteWriter.read_from(&self, InStream reader) @dynamic
 	}
 	if (self.bytes.len == 0)
 	{
-		self.ensure_capacity(16)!;
+		self.ensure_capacity(256)!;
 	}
 	while (true)
 	{