4 #include <sigc++/sigc++.h>
5 #include <msp/core/mutex.h>
14 Common interface for all I/O objects.
19 /** RAII synchronization primitive. Prevents concurrent access to the
20 target object during the lifetime of the Synchronize object. */
31 /** Emitted when there is no more data to be read. */
32 sigc::signal<void> signal_end_of_file;
34 /** Emitted when there is a nonlinearity in I/O (such as a file being
35 seeked) and any data buffered by upper layers needs to be flushed. */
36 sigc::signal<void> signal_flush_required;
38 /** Emitted when the object is deleted. Mainly for use by
40 sigc::signal<void> signal_deleted;
50 Base &operator=(const Base &);
54 /** Sets blocking mode. When blocking is enabled, most operations won't
55 return until they can make progress. When blocking is disabled, these
56 operations may return immediately with a return code indicating that nothing
59 Blocking is enabled by default. */
60 virtual void set_block(bool) { }
62 /** Returns the current mode flags. */
63 Mode get_mode() const { return mode; }
66 void check_access(Mode) const;
68 virtual unsigned do_write(const char *, unsigned) = 0;
69 virtual unsigned do_read(char *, unsigned) = 0;
72 /** Writes data from a buffer. Subject to blocking. Returns the number of
73 bytes written, which may be zero for a non-blockin operation. */
74 unsigned write(const char *b, unsigned c) { return do_write(b, c); }
76 /** Writes a string. This is identical to calling
77 write(s.data(), s.size()). */
78 unsigned write(const std::string &s) { return do_write(s.data(), s.size()); }
80 /** Writes a single character. This is identical to calling
82 virtual unsigned put(char c) { return do_write(&c, 1); }
84 /** Reads data into a buffer. Subject to blocking. Returns the number of
85 bytes read, which may be zero for a non-blocking operation. */
86 unsigned read(char *b, unsigned c) { return do_read(b, c); }
88 /** Reads characters up to the next linefeed or end-of-file. The linefeed
89 is not included in the line. Returns true if a line was successfully read,
91 virtual bool getline(std::string &);
93 /** Reads a single character. Returns -1 if no character was available due
94 to end-of-file or non-blocking operation. */
101 /** Returns the end-of-file flag. Note that some types of objects won't
102 indicate end-of-file until you try to read at least one byte past the actual
103 end, while others indicate it when you've read the last byte. */
104 bool eof() const { return eof_flag; }
106 /** Returns the system-level handle for the object. Used by Console to
107 perform redirections. */
108 virtual const Handle &get_handle(Mode);