conbuf.d

   1 module conbuf is aliced;
   2 private:
   3
   4 // ////////////////////////////////////////////////////////////////////////// //
   5 import core.sync.mutex : Mutex;
   6 __gshared Mutex conbufLock;
   7 shared static this () { conbufLock = new Mutex(); }
   8
   9
  10 // ////////////////////////////////////////////////////////////////////////// //
  11 enum ConBufSize = 256*1024;
  12 //enum ConBufSize = 64;
  13
  14 // each line in buffer ends with '\n'; we don't keep offsets or lengthes, as
  15 // it's fairly easy to search in buffer, and drawing console is not a common
  16 // thing, so it doesn't have to be superfast.
  17 __gshared char[ConBufSize] cbuf = 0;
  18 __gshared int cbufhead, cbuftail; // `cbuftail` points *at* last char
  19 shared static this () { cbuf.ptr[0] = '\n'; }
  20
  21
  22 // ////////////////////////////////////////////////////////////////////////// //
  23 public void cbufPut (const(char)[] chrs...) nothrow @trusted @nogc {
  24   foreach (char ch; chrs) {
  25     int np = (cbuftail+1)%ConBufSize;
  26     if (np == cbufhead) {
  27       // we have to make some room; delete top line for this
  28       for (;;) {
  29         char och = cbuf.ptr[cbufhead];
  30         cbufhead = (cbufhead+1)%ConBufSize;
  31         if (cbufhead == np || och == '\n') break;
  32       }
  33     }
  34     cbuf.ptr[np] = ch;
  35     cbuftail = np;
  36   }
  37 }
  38
  39
  40 // ////////////////////////////////////////////////////////////////////////// //
  41 public void conbufDump () {
  42   import std.stdio;
  43   int pp = cbufhead;
  44   stdout.writeln("==========================");
  45   for (;;) {
  46     if (cbuf.ptr[pp] == '\n') stdout.write('|');
  47     stdout.write(cbuf.ptr[pp]);
  48     if (pp == cbuftail) {
  49       if (cbuf.ptr[pp] != '\n') stdout.write('\n');
  50       break;
  51     }
  52     pp = (pp+1)%ConBufSize;
  53   }
  54 }
  55
  56
  57 // ////////////////////////////////////////////////////////////////////////// //
  58 version(test_cbuf) unittest {
  59
  60   conbufDump();
  61   cbufPut("boo\n"); conbufDump();
  62   cbufPut("this is another line\n"); conbufDump();
  63   cbufPut("one more line\n"); conbufDump();
  64   cbufPut("foo\n"); conbufDump();
  65   cbufPut("more lines!\n"); conbufDump();
  66   cbufPut("and even more lines!\n"); conbufDump();
  67   foreach (immutable idx; 0..256) {
  68     import std.string : format;
  69     cbufPut("line %s\n".format(idx));
  70     conbufDump();
  71   }
  72 }