InFile class

lib/core/SConscript

@@ -0,0 +1,4 @@
+# SConscript
+# Eryn Wells <eryn@erynwells.me>
+
+Library('erw', ['src/File.cc'])

lib/core/include/core/File.hh

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+/* File.hh
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * File interface.
+ */
+
+#include <bitset>
+#include <fstream>
+#include <memory>
+
+#include "String.hh"
+
+
+namespace erw {
+namespace core {
+
+struct File
+{
+    enum class SeekFrom {
+        /** Seek from the beginning of the file. */
+        Begin,
+        /** Seek from the current file offset. */
+        Here,
+        /** Seek from the end of the file. */
+        End,
+    };
+
+    typedef std::bitset<3> Mode;
+
+    static constexpr Mode In = Mode(1);
+    static constexpr Mode Out = Mode(2);
+    static constexpr Mode Binary = Mode(4);
+
+    /** Destructor. */
+    virtual ~File();
+
+    /** Seek to an absolute position in the file. */
+    virtual File& seek(size_t pos) = 0;
+
+    /**
+     * Seek to an `offset` from the given anchor point in the file.
+     * @see SeekFrom
+     */
+    virtual File& seek(ssize_t offset, SeekFrom from) = 0;
+
+protected:
+    /** Convert a File::Mode to an iostream openmode bitset. */
+    virtual std::ios_base::openmode modeToIOSMode(Mode mode);
+};
+
+
+/** File handle for reading. */
+struct InFile
+    : public File
+{
+    /** Open a file at `path` for reading. */
+    InFile(const String& path, File::Mode mode);
+    
+    /** Deleted copy constructor. File handles cannot be copied. */
+    InFile(const InFile& other) = delete;
+
+    /** Move `other` to this InFile. */
+    InFile(InFile&& other);
+
+    virtual ~InFile();
+
+    /** Move `other` to this InFile. File handles cannot be copied. */
+    InFile& operator=(InFile& other);
+
+    /** Read up to `count` characters into the provided `buffer`. */
+    InFile& read(char* buffer, ssize_t count);
+
+    /** @see File::seek */
+    InFile& seek(size_t pos) override;
+
+    /** @See File::seek */
+    InFile& seek(ssize_t pos, File::SeekFrom from) override;
+
+private:
+    std::ifstream mStream;
+
+    std::ios_base::openmode modeToIOSMode(File::Mode mode) override;
+};
+
+
+struct OutFile
+    : public File
+{
+    /** Write `count` characters from the provided `buffer` into this file. */
+    InFile& write(char* buffer, ssize_t count);
+
+    /** @see File::seek */
+    InFile& seek(size_t pos) override;
+
+    /** @See File::seek */
+    InFile& seek(ssize_t pos, File::SeekFrom from) override;
+
+private:
+    std::ofstream stream;
+};
+
+} /* namespace core */
+} /* namespace erw */

lib/core/src/File.cc

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+/* File.cc
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * Implementation of file handling.
+ */
+
+#include "core/File.hh"
+
+
+namespace erw {
+namespace core {
+
+#pragma mark - File
+
+File::~File()
+{ }
+
+
+/*
+ * InFile::modeToIOSMode --
+ */
+std::ios_base::openmode
+File::modeToIOSMode(Mode mode)
+{
+    std::ios_base::openmode openmode = 0;
+    if ((mode & In).any()) {
+        openmode |= std::ios_base::in;
+    }
+    if ((mode & Out).any()) {
+        openmode |= std::ios_base::out;
+    }
+    if ((mode & Binary).any()) {
+        openmode |= std::ios_base::binary;
+    }
+    return openmode;
+}
+
+#pragma mark - InFile
+
+/*
+ * InFile::InFile --
+ */
+InFile::InFile(const String& path,
+               InFile::Mode mode)
+    : mStream(path, modeToIOSMode(mode))
+{ }
+
+
+/*
+ * InFile::InFile --
+ */
+InFile::InFile(InFile&& other)
+    : mStream(std::move(other.mStream))
+{ }
+
+
+/*
+ * InFile::~InFile --
+ */
+InFile::~InFile()
+{ }
+
+
+/*
+ * InFile::operator= --
+ */
+InFile&
+InFile::operator=(InFile& other)
+{
+    mStream = std::move(other.mStream);
+    return *this;
+}
+
+
+/*
+ * InFile::read --
+ */
+InFile&
+InFile::read(char* buffer,
+             ssize_t count)
+{
+    mStream.read(buffer, count);
+    return *this;
+}
+
+
+/*
+ * InFile::seek --
+ */
+InFile&
+InFile::seek(size_t pos)
+{
+    mStream.seekg(pos);
+    return *this;
+}
+
+
+/*
+ * InFile::seek --
+ */
+InFile&
+InFile::seek(ssize_t off,
+             File::SeekFrom from)
+{
+    std::ios_base::seekdir dir;
+    switch (from) {
+        case File::SeekFrom::Begin:
+            dir = std::ios_base::beg;
+            break;
+        case File::SeekFrom::Here:
+            dir = std::ios_base::cur;
+            break;
+        case File::SeekFrom::End:
+            dir = std::ios_base::end;
+            break;
+    }
+    mStream.seekg(off, dir);
+    return *this;
+}
+
+
+/*
+ * InFile::modeToIOSMode --
+ */
+std::ios_base::openmode
+InFile::modeToIOSMode(File::Mode mode)
+{
+    // Ensure In flag is always set.
+    if (!(mode & File::In).any()) {
+        mode |= File::In;
+    }
+    return File::modeToIOSMode(mode);
+}
+
+#pragma mark - OutFile
+
+} /* namespace core */
+} /* namespace erw */