diff options
Diffstat (limited to 'appl/cmd/mash/history.b')
| -rw-r--r-- | appl/cmd/mash/history.b | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/appl/cmd/mash/history.b b/appl/cmd/mash/history.b new file mode 100644 index 00000000..7f7cf9b6 --- /dev/null +++ b/appl/cmd/mash/history.b @@ -0,0 +1,206 @@ +implement Mashbuiltin; + +# +# "history" builtin, defines: +# + +include "mash.m"; +include "mashparse.m"; + +mashlib: Mashlib; +chanfill: ChanFill; + +Env: import mashlib; +sys, bufio: import mashlib; + +Iobuf: import bufio; + +Hcmd: adt +{ + seek: int; + text: array of byte; +}; + +Reader: adt +{ + fid: int; + offset: int; + hint: int; + next: cyclic ref Reader; +}; + +history: array of ref Hcmd; +lhist: int; +nhist: int; +seek: int; +readers: ref Reader; +eof := array[0] of byte; + +# +# Interface to catch the use as a command. +# +init(nil: ref Draw->Context, args: list of string) +{ + raise "fail: " + hd args + " not loaded"; +} + +# +# Used by whatis. +# +name(): string +{ + return "history"; +} + +# +# Install commands. +# +mashinit(nil: list of string, lib: Mashlib, nil: Mashbuiltin, e: ref Env) +{ + mashlib = lib; + if (mashlib->histchan != nil) + return; + mashlib->startserve = 1; + nhist = 0; + lhist = 256; + history = array[lhist] of ref Hcmd; + seek = 0; + (f, c) := e.servefile(mashlib->HISTF); + spawn servehist(f, c); + (f, c) = e.servefile(mashlib->MASHF); + spawn servemash(f, c); +} + +mashcmd(nil: ref Env, nil: list of string) +{ +} + +addhist(b: array of byte) +{ + if (nhist == lhist) { + n := 3 * nhist / 4; + part := history[:n]; + part[:] = history[nhist - n:]; + nhist = n; + } + history[nhist] = ref Hcmd(seek, b); + nhist++; + seek += len b; +} + +getfid(fid: int, del: int): ref Reader +{ + prev: ref Reader; + for (r := readers; r != nil; r = r.next) { + if (r.fid == fid) { + if (del) { + if (prev == nil) + readers = r.next; + else + prev.next = r.next; + return nil; + } + return r; + } + prev = r; + } + o := 0; + if (nhist > 0) + o = history[0].seek; + return readers = ref Reader(fid, o, 0, readers); +} + +readhist(off, count, fid: int): (array of byte, string) +{ + r := getfid(fid, 0); + off += r.offset; + if (nhist == 0 || off >= seek) + return (eof, nil); + i := r.hint; + if (i >= nhist) + i = nhist - 1; + s := history[i].seek; + if (off == s) { + r.hint = i + 1; + return (history[i].text, nil); + } + if (off > s) { + do { + if (++i == nhist) + break; + s = history[i].seek; + } while (off >= s); + i--; + } else { + do { + if (--i < 0) + return (eof, "data truncated"); + s = history[i].seek; + } while (off < s); + } + r.hint = i + 1; + b := history[i].text; + if (off != s) + b = b[off - s:]; + return (b, nil); +} + +loadhist(data: array of byte, fid: int, wc: Sys->Rwrite, c: ref Sys->FileIO) +{ + in: ref Iobuf; + if (chanfill == nil) + chanfill = load ChanFill ChanFill->PATH; + if (chanfill != nil) + in = chanfill->init(data, fid, wc, c, mashlib->bufio); + if (in == nil) { + in = bufio->sopen(string data); + if (in == nil) { + wc <-= (0, mashlib->errstr()); + return; + } + wc <-= (len data, nil); + } + while ((s := in.gets('\n')) != nil) + addhist(array of byte s); + in.close(); +} + +servehist(f: string, c: ref Sys->FileIO) +{ + mashlib->reap(); + h := chan of array of byte; + mashlib->histchan = h; + for (;;) { + alt { + b := <-h => + addhist(b); + (off, count, fid, rc) := <-c.read => + if (rc == nil) { + getfid(fid, 1); + continue; + } + rc <-= readhist(off, count, fid); + (off, data, fid, wc) := <-c.write => + if (wc != nil) + loadhist(data, fid, wc, c); + } + } +} + +servemash(f: string, c: ref Sys->FileIO) +{ + mashlib->reap(); + for (;;) { + alt { + (off, count, fid, rc) := <-c.read => + if (rc != nil) + rc <-= (nil, "not supported"); + (off, data, fid, wc) := <-c.write => + if (wc != nil) { + wc <-= (len data, nil); + if (mashlib->servechan != nil && len data > 0) + mashlib->servechan <-= data; + } + } + } +} |