/src/tmux/control.c

Source
/* $OpenBSD$ */

/*
 * Copyright (c) 2012 Nicholas Marriott <nicholas.marriott@gmail.com>
 * Copyright (c) 2012 George Nachman <tmux@georgester.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

/*
 * Block of data to output. Each client has one "all" queue of blocks and
 * another queue for each pane (in struct client_offset). %output blocks are
 * added to both queues and other output lines (notifications) added only to
 * the client queue.
 *
 * When a client becomes writeable, data from blocks on the pane queue are sent
 * up to the maximum size (CLIENT_BUFFER_HIGH). If a block is entirely written,
 * it is removed from both pane and client queues and if this means non-%output
 * blocks are now at the head of the client queue, they are written.
 *
 * This means a %output block holds up any subsequent non-%output blocks until
 * it is written which enforces ordering even if the client cannot accept the
 * entire block in one go.
 */
struct control_block {
  size_t         size;
  char        *line;
  uint64_t       t;

  TAILQ_ENTRY(control_block)   entry;
  TAILQ_ENTRY(control_block)   all_entry;
};

/* Control client pane. */
struct control_pane {
  u_int        pane;

  /*
   * Offsets into the pane data. The first (offset) is the data we have
   * written; the second (queued) the data we have queued (pointed to by
   * a block).
   */
  struct window_pane_offset  offset;
  struct window_pane_offset  queued;

  int        flags;
#define CONTROL_PANE_OFF 0x1
#define CONTROL_PANE_PAUSED 0x2

  int        pending_flag;
  TAILQ_ENTRY(control_pane)  pending_entry;

  TAILQ_HEAD(, control_block)  blocks;

  RB_ENTRY(control_pane)     entry;
};
RB_HEAD(control_panes, control_pane);

/* Subscription pane. */
struct control_sub_pane {
  u_int        pane;
  u_int        idx;
  char        *last;

  RB_ENTRY(control_sub_pane)   entry;
};
RB_HEAD(control_sub_panes, control_sub_pane);

/* Subscription window. */
struct control_sub_window {
  u_int        window;
  u_int        idx;
  char        *last;

  RB_ENTRY(control_sub_window)   entry;
};
RB_HEAD(control_sub_windows, control_sub_window);

/* Control client subscription. */
struct control_sub {
  char        *name;
  char        *format;

  enum control_sub_type    type;
  u_int        id;

  char        *last;
  struct control_sub_panes   panes;
  struct control_sub_windows   windows;

  RB_ENTRY(control_sub)    entry;
};
RB_HEAD(control_subs, control_sub);

/* Control client state. */
struct control_state {
  struct control_panes     panes;

  TAILQ_HEAD(, control_pane)   pending_list;
  u_int        pending_count;

  TAILQ_HEAD(, control_block)  all_blocks;

  struct bufferevent    *read_event;
  struct bufferevent    *write_event;

  struct control_subs    subs;
  struct event       subs_timer;
};

/* Low and high watermarks. */
#define CONTROL_BUFFER_LOW 512
#define CONTROL_BUFFER_HIGH 8192

/* Minimum to write to each client. */
#define CONTROL_WRITE_MINIMUM 32

/* Maximum age for clients that are not using pause mode. */
#define CONTROL_MAXIMUM_AGE 300000

/* Flags to ignore client. */
#define CONTROL_IGNORE_FLAGS \
  (CLIENT_CONTROL_NOOUTPUT| \
   CLIENT_UNATTACHEDFLAGS)

/* Compare client panes. */
static int
control_pane_cmp(struct control_pane *cp1, struct control_pane *cp2)
{
  if (cp1->pane < cp2->pane)
    return (-1);
  if (cp1->pane > cp2->pane)
    return (1);
  return (0);
}
RB_GENERATE_STATIC(control_panes, control_pane, entry, control_pane_cmp);

/* Compare client subs. */
static int
control_sub_cmp(struct control_sub *csub1, struct control_sub *csub2)
{
  return (strcmp(csub1->name, csub2->name));
}
RB_GENERATE_STATIC(control_subs, control_sub, entry, control_sub_cmp);

/* Compare client subscription panes. */
static int
control_sub_pane_cmp(struct control_sub_pane *csp1,
    struct control_sub_pane *csp2)
{
  if (csp1->pane < csp2->pane)
    return (-1);
  if (csp1->pane > csp2->pane)
    return (1);
  if (csp1->idx < csp2->idx)
    return (-1);
  if (csp1->idx > csp2->idx)
    return (1);
  return (0);
}
RB_GENERATE_STATIC(control_sub_panes, control_sub_pane, entry,
    control_sub_pane_cmp);

/* Compare client subscription windows. */
static int
control_sub_window_cmp(struct control_sub_window *csw1,
    struct control_sub_window *csw2)
{
  if (csw1->window < csw2->window)
    return (-1);
  if (csw1->window > csw2->window)
    return (1);
  if (csw1->idx < csw2->idx)
    return (-1);
  if (csw1->idx > csw2->idx)
    return (1);
  return (0);
}
RB_GENERATE_STATIC(control_sub_windows, control_sub_window, entry,
    control_sub_window_cmp);

/* Free a subscription. */
static void
control_free_sub(struct control_state *cs, struct control_sub *csub)
{
  struct control_sub_pane   *csp, *csp1;
  struct control_sub_window *csw, *csw1;

  RB_FOREACH_SAFE(csp, control_sub_panes, &csub->panes, csp1) {
    RB_REMOVE(control_sub_panes, &csub->panes, csp);
    free(csp->last);
    free(csp);
  }
  RB_FOREACH_SAFE(csw, control_sub_windows, &csub->windows, csw1) {
    RB_REMOVE(control_sub_windows, &csub->windows, csw);
    free(csw->last);
    free(csw);
  }
  free(csub->last);

  RB_REMOVE(control_subs, &cs->subs, csub);
  free(csub->name);
  free(csub->format);
  free(csub);
}

/* Free a block. */
static void
control_free_block(struct control_state *cs, struct control_block *cb)
{
  free(cb->line);
  TAILQ_REMOVE(&cs->all_blocks, cb, all_entry);
  free(cb);
}

/* Get pane offsets for this client. */
static struct control_pane *
control_get_pane(struct client *c, struct window_pane *wp)
{
  struct control_state  *cs = c->control_state;
  struct control_pane  cp = { .pane = wp->id };

  return (RB_FIND(control_panes, &cs->panes, &cp));
}

/* Add pane offsets for this client. */
static struct control_pane *
control_add_pane(struct client *c, struct window_pane *wp)
{
  struct control_state  *cs = c->control_state;
  struct control_pane *cp;

  cp = control_get_pane(c, wp);
  if (cp != NULL)
    return (cp);

  cp = xcalloc(1, sizeof *cp);
  cp->pane = wp->id;
  RB_INSERT(control_panes, &cs->panes, cp);

  memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
  memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
  TAILQ_INIT(&cp->blocks);

  return (cp);
}

/* Discard output for a pane. */
static void
control_discard_pane(struct client *c, struct control_pane *cp)
{
  struct control_state  *cs = c->control_state;
  struct control_block  *cb, *cb1;

  TAILQ_FOREACH_SAFE(cb, &cp->blocks, entry, cb1) {
    TAILQ_REMOVE(&cp->blocks, cb, entry);
    control_free_block(cs, cb);
  }
}

/* Get actual pane for this client. */
static struct window_pane *
control_window_pane(struct client *c, u_int pane)
{
  struct window_pane  *wp;

  if (c->session == NULL)
    return (NULL);
  if ((wp = window_pane_find_by_id(pane)) == NULL)
    return (NULL);
  if (winlink_find_by_window(&c->session->windows, wp->window) == NULL)
    return (NULL);
  return (wp);
}

/* Reset control offsets. */
void
control_reset_offsets(struct client *c)
{
  struct control_state  *cs = c->control_state;
  struct control_pane *cp, *cp1;

  RB_FOREACH_SAFE(cp, control_panes, &cs->panes, cp1) {
    control_discard_pane(c, cp);
    RB_REMOVE(control_panes, &cs->panes, cp);
    free(cp);
  }

  TAILQ_INIT(&cs->pending_list);
  cs->pending_count = 0;
}

/* Get offsets for client. */
struct window_pane_offset *
control_pane_offset(struct client *c, struct window_pane *wp, int *off)
{
  struct control_state  *cs = c->control_state;
  struct control_pane *cp;

  if (c->flags & CLIENT_CONTROL_NOOUTPUT) {
    *off = 0;
    return (NULL);
  }

  cp = control_get_pane(c, wp);
  if (cp == NULL || (cp->flags & CONTROL_PANE_PAUSED)) {
    *off = 0;
    return (NULL);
  }
  if (cp->flags & CONTROL_PANE_OFF) {
    *off = 1;
    return (NULL);
  }
  *off = (EVBUFFER_LENGTH(cs->write_event->output) >= CONTROL_BUFFER_LOW);
  return (&cp->offset);
}

/* Set pane as on. */
void
control_set_pane_on(struct client *c, struct window_pane *wp)
{
  struct control_pane *cp;

  cp = control_get_pane(c, wp);
  if (cp != NULL && (cp->flags & CONTROL_PANE_OFF)) {
    cp->flags &= ~CONTROL_PANE_OFF;
    memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
    memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
  }
}

/* Set pane as off. */
void
control_set_pane_off(struct client *c, struct window_pane *wp)
{
  struct control_pane *cp;

  cp = control_add_pane(c, wp);
  control_discard_pane(c, cp);
  memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
  memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
  cp->flags |= CONTROL_PANE_OFF;
}

/* Continue a paused pane. */
void
control_continue_pane(struct client *c, struct window_pane *wp)
{
  struct control_pane *cp;

  cp = control_get_pane(c, wp);
  if (cp != NULL && (cp->flags & CONTROL_PANE_PAUSED)) {
    cp->flags &= ~CONTROL_PANE_PAUSED;
    memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
    memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
    control_write(c, "%%continue %%%u", wp->id);
  }
}

/* Pause a pane. */
void
control_pause_pane(struct client *c, struct window_pane *wp)
{
  struct control_pane *cp;

  cp = control_add_pane(c, wp);
  if (~cp->flags & CONTROL_PANE_PAUSED) {
    cp->flags |= CONTROL_PANE_PAUSED;
    control_discard_pane(c, cp);
    control_write(c, "%%pause %%%u", wp->id);
  }
}

/* Write a line. */
static void printflike(2, 0)
control_vwrite(struct client *c, const char *fmt, va_list ap)
{
  struct control_state  *cs = c->control_state;
  char      *s;

  xvasprintf(&s, fmt, ap);
  log_debug("%s: %s: writing line: %s", __func__, c->name, s);

  bufferevent_write(cs->write_event, s, strlen(s));
  bufferevent_write(cs->write_event, "\n", 1);

  bufferevent_enable(cs->write_event, EV_WRITE);
  free(s);
}

/* Write a line. */
void
control_write(struct client *c, const char *fmt, ...)
{
  struct control_state  *cs = c->control_state;
  struct control_block  *cb;
  va_list      ap;

  va_start(ap, fmt);

  if (TAILQ_EMPTY(&cs->all_blocks)) {
    control_vwrite(c, fmt, ap);
    va_end(ap);
    return;
  }

  cb = xcalloc(1, sizeof *cb);
  xvasprintf(&cb->line, fmt, ap);
  TAILQ_INSERT_TAIL(&cs->all_blocks, cb, all_entry);
  cb->t = get_timer();

  log_debug("%s: %s: storing line: %s", __func__, c->name, cb->line);
  bufferevent_enable(cs->write_event, EV_WRITE);

  va_end(ap);
}

/* Check age for this pane. */
static int
control_check_age(struct client *c, struct window_pane *wp,
    struct control_pane *cp)
{
  struct control_block  *cb;
  uint64_t     t, age;

  cb = TAILQ_FIRST(&cp->blocks);
  if (cb == NULL)
    return (0);
  t = get_timer();
  if (cb->t >= t)
    return (0);

  age = t - cb->t;
  log_debug("%s: %s: %%%u is %llu behind", __func__, c->name, wp->id,
      (unsigned long long)age);

  if (c->flags & CLIENT_CONTROL_PAUSEAFTER) {
    if (age < c->pause_age)
      return (0);
    cp->flags |= CONTROL_PANE_PAUSED;
    control_discard_pane(c, cp);
    control_write(c, "%%pause %%%u", wp->id);
  } else {
    if (age < CONTROL_MAXIMUM_AGE)
      return (0);
    c->exit_message = xstrdup("too far behind");
    c->flags |= CLIENT_EXIT;
    control_discard(c);
  }
  return (1);
}

/* Write output from a pane. */
void
control_write_output(struct client *c, struct window_pane *wp)
{
  struct control_state  *cs = c->control_state;
  struct control_pane *cp;
  struct control_block  *cb;
  size_t       new_size;

  if (winlink_find_by_window(&c->session->windows, wp->window) == NULL)
    return;

  if (c->flags & CONTROL_IGNORE_FLAGS) {
    cp = control_get_pane(c, wp);
    if (cp != NULL)
      goto ignore;
    return;
  }
  cp = control_add_pane(c, wp);
  if (cp->flags & (CONTROL_PANE_OFF|CONTROL_PANE_PAUSED))
    goto ignore;
  if (control_check_age(c, wp, cp))
    return;

  window_pane_get_new_data(wp, &cp->queued, &new_size);
  if (new_size == 0)
    return;
  window_pane_update_used_data(wp, &cp->queued, new_size);

  cb = xcalloc(1, sizeof *cb);
  cb->size = new_size;
  TAILQ_INSERT_TAIL(&cs->all_blocks, cb, all_entry);
  cb->t = get_timer();

  TAILQ_INSERT_TAIL(&cp->blocks, cb, entry);
  log_debug("%s: %s: new output block of %zu for %%%u", __func__, c->name,
      cb->size, wp->id);

  if (!cp->pending_flag) {
    log_debug("%s: %s: %%%u now pending", __func__, c->name,
        wp->id);
    TAILQ_INSERT_TAIL(&cs->pending_list, cp, pending_entry);
    cp->pending_flag = 1;
    cs->pending_count++;
  }
  bufferevent_enable(cs->write_event, EV_WRITE);
  return;

ignore:
  log_debug("%s: %s: ignoring pane %%%u", __func__, c->name, wp->id);
  window_pane_update_used_data(wp, &cp->offset, SIZE_MAX);
  window_pane_update_used_data(wp, &cp->queued, SIZE_MAX);
}

/* Control client error callback. */
static enum cmd_retval
control_error(struct cmdq_item *item, void *data)
{
  struct client *c = cmdq_get_client(item);
  char    *error = data;

  cmdq_guard(item, "begin", 1);
  control_write(c, "parse error: %s", error);
  cmdq_guard(item, "error", 1);

  free(error);
  return (CMD_RETURN_NORMAL);
}

/* Control client error callback. */
static void
control_error_callback(__unused struct bufferevent *bufev,
    __unused short what, void *data)
{
  struct client *c = data;

  c->flags |= CLIENT_EXIT;
}

/* Control client input callback. Read lines and fire commands. */
static void
control_read_callback(__unused struct bufferevent *bufev, void *data)
{
  struct client   *c = data;
  struct control_state  *cs = c->control_state;
  struct evbuffer   *buffer = cs->read_event->input;
  char      *line, *error;
  struct cmdq_state *state;
  enum cmd_parse_status  status;

  for (;;) {
    line = evbuffer_readln(buffer, NULL, EVBUFFER_EOL_LF);
    if (line == NULL)
      break;
    log_debug("%s: %s: %s", __func__, c->name, line);
    if (*line == '\0') { /* empty line detach */
      free(line);
      c->flags |= CLIENT_EXIT;
      break;
    }

    state = cmdq_new_state(NULL, NULL, CMDQ_STATE_CONTROL);
    status = cmd_parse_and_append(line, NULL, c, state, &error);
    if (status == CMD_PARSE_ERROR)
      cmdq_append(c, cmdq_get_callback(control_error, error));
    cmdq_free_state(state);

    free(line);
  }
}

/* Does this control client have outstanding data to write? */
int
control_all_done(struct client *c)
{
  struct control_state  *cs = c->control_state;

  if (!TAILQ_EMPTY(&cs->all_blocks))
    return (0);
  return (EVBUFFER_LENGTH(cs->write_event->output) == 0);
}

/* Flush all blocks until output. */
static void
control_flush_all_blocks(struct client *c)
{
  struct control_state  *cs = c->control_state;
  struct control_block  *cb, *cb1;

  TAILQ_FOREACH_SAFE(cb, &cs->all_blocks, all_entry, cb1) {
    if (cb->size != 0)
      break;
    log_debug("%s: %s: flushing line: %s", __func__, c->name,
        cb->line);

    bufferevent_write(cs->write_event, cb->line, strlen(cb->line));
    bufferevent_write(cs->write_event, "\n", 1);
    control_free_block(cs, cb);
  }
}

/* Append data to buffer. */
static struct evbuffer *
control_append_data(struct client *c, struct control_pane *cp, uint64_t age,
    struct evbuffer *message, struct window_pane *wp, size_t size)
{
  u_char  *new_data;
  size_t   new_size, start;
  u_int  i;

  if (message == NULL) {
    message = evbuffer_new();
    if (message == NULL)
      fatalx("out of memory");
    if (c->flags & CLIENT_CONTROL_PAUSEAFTER) {
      evbuffer_add_printf(message,
          "%%extended-output %%%u %llu : ", wp->id,
          (unsigned long long)age);
    } else
      evbuffer_add_printf(message, "%%output %%%u ", wp->id);
  }

  new_data = window_pane_get_new_data(wp, &cp->offset, &new_size);
  if (new_size < size)
    fatalx("not enough data: %zu < %zu", new_size, size);
  for (i = 0; i < size; i++) {
    if (new_data[i] < ' ' || new_data[i] == '\\') {
      evbuffer_add_printf(message, "\\%03o", new_data[i]);
    } else {
      start = i;
      while (i + 1 < size &&
          new_data[i + 1] >= ' ' &&
          new_data[i + 1] != '\\')
        i++;
      evbuffer_add(message, new_data + start, i - start + 1);
    }
  }
  window_pane_update_used_data(wp, &cp->offset, size);
  return (message);
}

/* Write buffer. */
static void
control_write_data(struct client *c, struct evbuffer *message)
{
  struct control_state  *cs = c->control_state;

  log_debug("%s: %s: %.*s", __func__, c->name,
      (int)EVBUFFER_LENGTH(message), EVBUFFER_DATA(message));

  evbuffer_add(message, "\n", 1);
  bufferevent_write_buffer(cs->write_event, message);
  evbuffer_free(message);
}

/* Write output to client. */
static int
control_write_pending(struct client *c, struct control_pane *cp, size_t limit)
{
  struct control_state  *cs = c->control_state;
  struct window_pane  *wp = NULL;
  struct evbuffer   *message = NULL;
  size_t       used = 0, size;
  struct control_block  *cb, *cb1;
  uint64_t     age, t = get_timer();

  wp = control_window_pane(c, cp->pane);
  if (wp == NULL || wp->fd == -1) {
    TAILQ_FOREACH_SAFE(cb, &cp->blocks, entry, cb1) {
      TAILQ_REMOVE(&cp->blocks, cb, entry);
      control_free_block(cs, cb);
    }
    control_flush_all_blocks(c);
    return (0);
  }

  while (used != limit && !TAILQ_EMPTY(&cp->blocks)) {
    if (control_check_age(c, wp, cp)) {
      if (message != NULL)
        evbuffer_free(message);
      message = NULL;
      break;
    }

    cb = TAILQ_FIRST(&cp->blocks);
    if (cb->t < t)
      age = t - cb->t;
    else
      age = 0;
    log_debug("%s: %s: output block %zu (age %llu) for %%%u "
        "(used %zu/%zu)", __func__, c->name, cb->size,
        (unsigned long long)age, cp->pane, used, limit);

    size = cb->size;
    if (size > limit - used)
      size = limit - used;
    used += size;

    message = control_append_data(c, cp, age, message, wp, size);

    cb->size -= size;
    if (cb->size == 0) {
      TAILQ_REMOVE(&cp->blocks, cb, entry);
      control_free_block(cs, cb);

      cb = TAILQ_FIRST(&cs->all_blocks);
      if (cb != NULL && cb->size == 0) {
        if (wp != NULL && message != NULL) {
          control_write_data(c, message);
          message = NULL;
        }
        control_flush_all_blocks(c);
      }
    }
  }
  if (message != NULL)
    control_write_data(c, message);
  return (!TAILQ_EMPTY(&cp->blocks));
}

/* Control client write callback. */
static void
control_write_callback(__unused struct bufferevent *bufev, void *data)
{
  struct client   *c = data;
  struct control_state  *cs = c->control_state;
  struct control_pane *cp, *cp1;
  struct evbuffer   *evb = cs->write_event->output;
  size_t       space, limit;

  control_flush_all_blocks(c);

  while (EVBUFFER_LENGTH(evb) < CONTROL_BUFFER_HIGH) {
    if (cs->pending_count == 0)
      break;
    space = CONTROL_BUFFER_HIGH - EVBUFFER_LENGTH(evb);
    log_debug("%s: %s: %zu bytes available, %u panes", __func__,
        c->name, space, cs->pending_count);

    limit = (space / cs->pending_count / 3); /* 3 bytes for \xxx */
    if (limit < CONTROL_WRITE_MINIMUM)
      limit = CONTROL_WRITE_MINIMUM;

    TAILQ_FOREACH_SAFE(cp, &cs->pending_list, pending_entry, cp1) {
      if (EVBUFFER_LENGTH(evb) >= CONTROL_BUFFER_HIGH)
        break;
      if (control_write_pending(c, cp, limit))
        continue;
      TAILQ_REMOVE(&cs->pending_list, cp, pending_entry);
      cp->pending_flag = 0;
      cs->pending_count--;
    }
  }
  if (EVBUFFER_LENGTH(evb) == 0)
    bufferevent_disable(cs->write_event, EV_WRITE);
}

/* Initialize for control mode. */
void
control_start(struct client *c)
{
  struct control_state  *cs;

  if (c->flags & CLIENT_CONTROLCONTROL) {
    close(c->out_fd);
    c->out_fd = -1;
  } else
    setblocking(c->out_fd, 0);
  setblocking(c->fd, 0);

  cs = c->control_state = xcalloc(1, sizeof *cs);
  RB_INIT(&cs->panes);
  TAILQ_INIT(&cs->pending_list);
  TAILQ_INIT(&cs->all_blocks);
  RB_INIT(&cs->subs);

  cs->read_event = bufferevent_new(c->fd, control_read_callback,
      control_write_callback, control_error_callback, c);
  if (cs->read_event == NULL)
    fatalx("out of memory");

  if (c->flags & CLIENT_CONTROLCONTROL)
    cs->write_event = cs->read_event;
  else {
    cs->write_event = bufferevent_new(c->out_fd, NULL,
        control_write_callback, control_error_callback, c);
    if (cs->write_event == NULL)
      fatalx("out of memory");
  }
  bufferevent_setwatermark(cs->write_event, EV_WRITE, CONTROL_BUFFER_LOW,
      0);

  if (c->flags & CLIENT_CONTROLCONTROL) {
    bufferevent_write(cs->write_event, "\033P1000p", 7);
    bufferevent_enable(cs->write_event, EV_WRITE);
  }
}

/* Control client ready. */
void
control_ready(struct client *c)
{
  bufferevent_enable(c->control_state->read_event, EV_READ);
}

/* Discard all output for a client. */
void
control_discard(struct client *c)
{
  struct control_state  *cs = c->control_state;
  struct control_pane *cp;

  RB_FOREACH(cp, control_panes, &cs->panes)
    control_discard_pane(c, cp);
  bufferevent_disable(cs->read_event, EV_READ);
}

/* Stop control mode. */
void
control_stop(struct client *c)
{
  struct control_state  *cs = c->control_state;
  struct control_block  *cb, *cb1;
  struct control_sub  *csub, *csub1;

  if (cs == NULL)
    return;

  if (~c->flags & CLIENT_CONTROLCONTROL)
    bufferevent_free(cs->write_event);
  bufferevent_free(cs->read_event);

  RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1)
    control_free_sub(cs, csub);
  if (evtimer_initialized(&cs->subs_timer))
    evtimer_del(&cs->subs_timer);

  control_reset_offsets(c);
  TAILQ_FOREACH_SAFE(cb, &cs->all_blocks, all_entry, cb1)
    control_free_block(cs, cb);

  c->control_state = NULL;
  free(cs);
}

/* Check session subscription. */
static void
control_check_subs_session(struct client *c, struct control_sub *csub,
    struct format_tree *ft)
{
  struct session    *s = c->session;
  char      *value;

  value = format_expand(ft, csub->format);

  if (csub->last != NULL && strcmp(value, csub->last) == 0) {
    free(value);
    return;
  }
  control_write(c,
      "%%subscription-changed %s $%u - - - : %s",
      csub->name, s->id, value);
  free(csub->last);
  csub->last = value;
}

/* Check pane subscription. */
static void
control_check_subs_pane(struct client *c, struct control_sub *csub)
{
  struct session    *s = c->session;
  struct window_pane  *wp;
  struct window   *w;
  struct winlink    *wl;
  struct format_tree  *ft;
  char      *value;
  struct control_sub_pane *csp, find;

  wp = window_pane_find_by_id(csub->id);
  if (wp == NULL || wp->fd == -1)
    return;
  w = wp->window;

  TAILQ_FOREACH(wl, &w->winlinks, wentry) {
    if (wl->session != s)
      continue;

    ft = format_create_defaults(NULL, c, s, wl, wp);
    value = format_expand(ft, csub->format);
    format_free(ft);

    find.pane = wp->id;
    find.idx = wl->idx;

    csp = RB_FIND(control_sub_panes, &csub->panes, &find);
    if (csp == NULL) {
      csp = xcalloc(1, sizeof *csp);
      csp->pane = wp->id;
      csp->idx = wl->idx;
      RB_INSERT(control_sub_panes, &csub->panes, csp);
    }

    if (csp->last != NULL && strcmp(value, csp->last) == 0) {
      free(value);
      continue;
    }
    control_write(c,
        "%%subscription-changed %s $%u @%u %u %%%u : %s",
        csub->name, s->id, w->id, wl->idx, wp->id, value);
    free(csp->last);
    csp->last = value;
  }
}

/* Check all-panes subscription for a pane. */
static void
control_check_subs_all_panes_one(struct client *c, struct control_sub *csub,
    struct format_tree *ft, struct winlink *wl, struct window_pane *wp)
{
  struct session    *s = c->session;
  struct window   *w = wl->window;
  char      *value;
  struct control_sub_pane *csp, find;

  value = format_expand(ft, csub->format);

  find.pane = wp->id;
  find.idx = wl->idx;

  csp = RB_FIND(control_sub_panes, &csub->panes, &find);
  if (csp == NULL) {
    csp = xcalloc(1, sizeof *csp);
    csp->pane = wp->id;
    csp->idx = wl->idx;
    RB_INSERT(control_sub_panes, &csub->panes, csp);
  }

  if (csp->last != NULL && strcmp(value, csp->last) == 0) {
    free(value);
    return;
  }
  control_write(c,
      "%%subscription-changed %s $%u @%u %u %%%u : %s",
      csub->name, s->id, w->id, wl->idx, wp->id, value);
  free(csp->last);
  csp->last = value;
}

/* Check window subscription. */
static void
control_check_subs_window(struct client *c, struct control_sub *csub)
{
  struct session      *s = c->session;
  struct window     *w;
  struct winlink      *wl;
  struct format_tree    *ft;
  char        *value;
  struct control_sub_window *csw, find;

  w = window_find_by_id(csub->id);
  if (w == NULL)
    return;

  TAILQ_FOREACH(wl, &w->winlinks, wentry) {
    if (wl->session != s)
      continue;

    ft = format_create_defaults(NULL, c, s, wl, NULL);
    value = format_expand(ft, csub->format);
    format_free(ft);

    find.window = w->id;
    find.idx = wl->idx;

    csw = RB_FIND(control_sub_windows, &csub->windows, &find);
    if (csw == NULL) {
      csw = xcalloc(1, sizeof *csw);
      csw->window = w->id;
      csw->idx = wl->idx;
      RB_INSERT(control_sub_windows, &csub->windows, csw);
    }

    if (csw->last != NULL && strcmp(value, csw->last) == 0) {
      free(value);
      continue;
    }
    control_write(c,
        "%%subscription-changed %s $%u @%u %u - : %s",
        csub->name, s->id, w->id, wl->idx, value);
    free(csw->last);
    csw->last = value;
  }
}

/* Check all-windows subscription for a window. */
static void
control_check_subs_all_windows_one(struct client *c, struct control_sub *csub,
    struct format_tree *ft, struct winlink *wl)
{
  struct session      *s = c->session;
  struct window     *w = wl->window;
  char        *value;
  struct control_sub_window *csw, find;

  value = format_expand(ft, csub->format);

  find.window = w->id;
  find.idx = wl->idx;

  csw = RB_FIND(control_sub_windows, &csub->windows, &find);
  if (csw == NULL) {
    csw = xcalloc(1, sizeof *csw);
    csw->window = w->id;
    csw->idx = wl->idx;
    RB_INSERT(control_sub_windows, &csub->windows, csw);
  }

  if (csw->last != NULL && strcmp(value, csw->last) == 0) {
    free(value);
    return;
  }
  control_write(c,
      "%%subscription-changed %s $%u @%u %u - : %s",
      csub->name, s->id, w->id, wl->idx, value);
  free(csw->last);
  csw->last = value;
}

/* Check subscriptions timer. */
static void
control_check_subs_timer(__unused int fd, __unused short events, void *data)
{
  struct client   *c = data;
  struct control_state  *cs = c->control_state;
  struct control_sub  *csub, *csub1;
  struct session    *s = c->session;
  struct format_tree  *ft;
  struct winlink    *wl;
  struct window_pane  *wp;
  struct timeval     tv = { .tv_sec = 1 };
  int      have_session = 0, have_all_panes = 0;
  int      have_all_windows = 0;

  log_debug("%s: timer fired", __func__);
  evtimer_add(&cs->subs_timer, &tv);

  if (s == NULL)
    return;

  /* Find which subscription types are present. */
  RB_FOREACH(csub, control_subs, &cs->subs) {
    switch (csub->type) {
    case CONTROL_SUB_SESSION:
      have_session = 1;
      break;
    case CONTROL_SUB_ALL_PANES:
      have_all_panes = 1;
      break;
    case CONTROL_SUB_ALL_WINDOWS:
      have_all_windows = 1;
      break;
    default:
      break;
    }
  }

  /* Check session subscriptions. */
  if (have_session) {
    ft = format_create_defaults(NULL, c, s, NULL, NULL);
    RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
      if (csub->type == CONTROL_SUB_SESSION)
        control_check_subs_session(c, csub, ft);
    }
    format_free(ft);
  }

  /* Check pane and window subscriptions. */
  RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
    switch (csub->type) {
    case CONTROL_SUB_PANE:
      control_check_subs_pane(c, csub);
      break;
    case CONTROL_SUB_WINDOW:
      control_check_subs_window(c, csub);
      break;
    case CONTROL_SUB_SESSION:
    case CONTROL_SUB_ALL_PANES:
    case CONTROL_SUB_ALL_WINDOWS:
      break;
    }
  }

  /* Check all-panes subscriptions. */
  if (have_all_panes) {
    RB_FOREACH(wl, winlinks, &s->windows) {
      TAILQ_FOREACH(wp, &wl->window->panes, entry) {
        ft = format_create_defaults(NULL, c, s, wl, wp);
        RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
            csub1) {
          if (csub->type != CONTROL_SUB_ALL_PANES)
            continue;
          control_check_subs_all_panes_one(c,
              csub, ft, wl, wp);
        }
        format_free(ft);
      }
    }
  }

  /* Check all-windows subscriptions. */
  if (have_all_windows) {
    RB_FOREACH(wl, winlinks, &s->windows) {
      ft = format_create_defaults(NULL, c, s, wl, NULL);
      RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
          csub1) {
        if (csub->type != CONTROL_SUB_ALL_WINDOWS)
          continue;
        control_check_subs_all_windows_one(c, csub, ft,
            wl);
      }
      format_free(ft);
    }
  }
}

/* Add a subscription. */
void
control_add_sub(struct client *c, const char *name, enum control_sub_type type,
    int id, const char *format)
{
  struct control_state  *cs = c->control_state;
  struct control_sub  *csub, find;
  struct timeval     tv = { .tv_sec = 1 };

  find.name = (char *)name;
  if ((csub = RB_FIND(control_subs, &cs->subs, &find)) != NULL)
    control_free_sub(cs, csub);

  csub = xcalloc(1, sizeof *csub);
  csub->name = xstrdup(name);
  csub->type = type;
  csub->id = id;
  csub->format = xstrdup(format);
  RB_INSERT(control_subs, &cs->subs, csub);

  RB_INIT(&csub->panes);
  RB_INIT(&csub->windows);

  if (!evtimer_initialized(&cs->subs_timer))
    evtimer_set(&cs->subs_timer, control_check_subs_timer, c);
  if (!evtimer_pending(&cs->subs_timer, NULL))
    evtimer_add(&cs->subs_timer, &tv);
}

/* Remove a subscription. */
void
control_remove_sub(struct client *c, const char *name)
{
  struct control_state  *cs = c->control_state;
  struct control_sub  *csub, find;

  find.name = (char *)name;
  if ((csub = RB_FIND(control_subs, &cs->subs, &find)) != NULL)
    control_free_sub(cs, csub);
  if (RB_EMPTY(&cs->subs))
    evtimer_del(&cs->subs_timer);
}

Coverage Report

Created: 2026-06-12 06:51