4 #include <sigc++/sigc++.h>
5 #include <msp/core/mutex.h>
14 Common interface for all I/O objects.
16 A derived class must call set_events(P_NONE) before it is destroyed to avoid
17 leaving stale pointers in an EventDispatcher.
22 /** RAII synchronization primitive. Prevents concurrent access to the
23 target object during the lifetime of the Synchronize object. */
34 /** Emitted when there is no more data to be read. */
35 sigc::signal<void> signal_end_of_file;
37 /** Emitted when there is a nonlinearity in I/O (such as a file being
38 seeked) and any data buffered by upper layers needs to be flushed. */
39 sigc::signal<void> signal_flush_required;
41 /** Emitted when the object is deleted. Mainly for use by
43 sigc::signal<void> signal_deleted;
53 Base &operator=(const Base &);
57 /** Sets blocking mode. When blocking is enabled, most operations won't
58 return until they can make progress. When blocking is disabled, these
59 operations may return immediately with a return code indicating that nothing
62 Blocking is enabled by default. */
63 virtual void set_block(bool) { }
65 /** Returns the current mode flags. */
66 Mode get_mode() const { return mode; }
69 void check_access(Mode) const;
71 virtual unsigned do_write(const char *, unsigned) = 0;
72 virtual unsigned do_read(char *, unsigned) = 0;
75 /** Writes data from a buffer. Subject to blocking. Returns the number of
76 bytes written, which may be zero for a non-blockin operation. */
77 unsigned write(const char *b, unsigned c) { return do_write(b, c); }
79 /** Writes a string. This is identical to calling
80 write(s.data(), s.size()). */
81 unsigned write(const std::string &s) { return do_write(s.data(), s.size()); }
83 /** Writes a single character. This is identical to calling
85 virtual unsigned put(char c) { return do_write(&c, 1); }
87 /** Reads data into a buffer. Subject to blocking. Returns the number of
88 bytes read, which may be zero for a non-blocking operation. */
89 unsigned read(char *b, unsigned c) { return do_read(b, c); }
91 /** Reads characters up to the next linefeed or end-of-file. The linefeed
92 is not included in the line. Returns true if a line was successfully read,
94 virtual bool getline(std::string &);
96 /** Reads a single character. Returns -1 if no character was available due
97 to end-of-file or non-blocking operation. */
104 /** Returns the end-of-file flag. Note that some types of objects won't
105 indicate end-of-file until you try to read at least one byte past the actual
106 end, while others indicate it when you've read the last byte. */
107 bool eof() const { return eof_flag; }
109 /** Returns the system-level handle for the object. Used by Console to
110 perform redirections. */
111 virtual const Handle &get_handle(Mode);