Libraries: Move to Userland/Libraries/

Userland/Libraries/LibCore/IODevice.h

@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Forward.h>
+#include <LibCore/Object.h>
+
+namespace Core {
+
+// This is not necessarily a valid iterator in all contexts,
+// if we had concepts, this would be InputIterator, not Copyable, Movable.
+class LineIterator {
+    AK_MAKE_NONCOPYABLE(LineIterator);
+
+public:
+    explicit LineIterator(IODevice&, bool is_end = false);
+
+    bool operator==(const LineIterator& other) const { return &other == this || (at_end() && other.is_end()) || (other.at_end() && is_end()); }
+    bool is_end() const { return m_is_end; }
+    bool at_end() const;
+
+    LineIterator& operator++();
+
+    StringView operator*() const { return m_buffer; }
+
+private:
+    NonnullRefPtr<IODevice> m_device;
+    bool m_is_end { false };
+    String m_buffer;
+};
+
+class IODevice : public Object {
+    C_OBJECT_ABSTRACT(IODevice)
+public:
+    enum OpenMode {
+        NotOpen = 0,
+        ReadOnly = 1,
+        WriteOnly = 2,
+        ReadWrite = 3,
+        Append = 4,
+        Truncate = 8,
+        MustBeNew = 16,
+    };
+
+    virtual ~IODevice() override;
+
+    int fd() const { return m_fd; }
+    unsigned mode() const { return m_mode; }
+    bool is_open() const { return m_mode != NotOpen; }
+    bool eof() const { return m_eof; }
+
+    int error() const { return m_error; }
+    const char* error_string() const;
+
+    bool has_error() const { return m_error != 0; }
+
+    int read(u8* buffer, int length);
+
+    ByteBuffer read(size_t max_size);
+    ByteBuffer read_all();
+    String read_line(size_t max_size = 16384);
+
+    bool write(const u8*, int size);
+    bool write(const StringView&);
+
+    bool truncate(off_t);
+
+    bool can_read_line() const;
+
+    bool can_read() const;
+
+    enum class SeekMode {
+        SetPosition,
+        FromCurrentPosition,
+        FromEndPosition,
+    };
+
+    bool seek(i64, SeekMode = SeekMode::SetPosition, off_t* = nullptr);
+
+    virtual bool open(IODevice::OpenMode) = 0;
+    virtual bool close();
+
+    int printf(const char*, ...);
+
+    LineIterator line_begin() & { return LineIterator(*this); }
+    LineIterator line_end() { return LineIterator(*this, true); }
+
+protected:
+    explicit IODevice(Object* parent = nullptr);
+
+    void set_fd(int);
+    void set_mode(OpenMode mode) { m_mode = mode; }
+    void set_error(int error) const { m_error = error; }
+    void set_eof(bool eof) const { m_eof = eof; }
+
+    virtual void did_update_fd(int) { }
+
+private:
+    bool populate_read_buffer() const;
+    bool can_read_from_fd() const;
+
+    int m_fd { -1 };
+    OpenMode m_mode { NotOpen };
+    mutable int m_error { 0 };
+    mutable bool m_eof { false };
+    mutable Vector<u8> m_buffered_data;
+};
+
+}