/src/libwebsockets/lib/misc/dlo/dlo.c

Source
/*
 * lws abstract display
 *
 * Copyright (C) 2019 - 2022 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Display List Object handling
 */

#include <private-lib-core.h>
#include "private-lib-drivers-display-dlo.h"

#define dlodump_loglevel                LLL_NOTICE
#if (_LWS_ENABLED_LOGS & dlodump_loglevel)
#define lwsl_dlodump(...)               _lws_log(dlodump_loglevel, __VA_ARGS__)
#else
#define lwsl_dlodump(...)
#endif

void
lws_display_dl_init(lws_displaylist_t *dl, lws_display_state_t *ds)
{
  lws_dll2_owner_clear(&dl->dl);
  dl->ds = ds;
}

int
lws_display_dlo_add(lws_displaylist_t *dl, lws_dlo_t *dlo_parent, lws_dlo_t *dlo)
{
  if (!dlo_parent && !dl->dl.head) {
    lws_dll2_add_tail(&dlo->list, &dl->dl);

    return 0;
  }

  if (!dlo_parent) {
    if (!dl->dl.head)
      return 0;

    dlo_parent = lws_container_of(dl->dl.head, lws_dlo_t, list);
  }

  lws_dll2_add_tail(&dlo->list, &dlo_parent->children);

  return 0;
}

void
lws_surface_set_px(const lws_surface_info_t *ic, uint8_t *line, int x,
       const lws_display_colour_t *c)
{
  unsigned int alpha, ialpha;
  lws_display_colour_t oc;
  lws_display_colour_t y;
  uint8_t rgb[3];

  if (x < 0 || x >= ic->wh_px[0].whole)
    return;

  /*
   * All alpha composition takes place at 8bpp grey or 24bpp
   */

  if (ic->greyscale) {

    /* line composition buffer is 8-bit Y per pixel */

    oc = line[x];
    alpha = LWSDC_ALPHA(*c);
    ialpha = 255 - alpha;

    y = RGB_TO_Y(LWSDC_R(*c), LWSDC_G(*c), LWSDC_B(*c));

    line[x] = (uint8_t)(((y * alpha) / 255) +
         ((LWSDC_R(oc) * ialpha) / 255));
    return;
  }

  /* line composition buffer is 24-bit RGB per pixel */

  line += (ic->render_to_rgba ? 4 : 3) * x;

  alpha = LWSDC_ALPHA(*c);
  ialpha = 255 - alpha;

  rgb[0] = (uint8_t)(((LWSDC_R(*c) * alpha) / 255) +
         ((line[0] * ialpha) / 255));
  rgb[1] = (uint8_t)(((LWSDC_G(*c) * alpha) / 255) +
         ((line[1] * ialpha) / 255));
  rgb[2] = (uint8_t)(((LWSDC_B(*c) * alpha) / 255) +
         ((line[2] * ialpha) / 255));

  *line++ = rgb[0];
  *line++ = rgb[1];
  *line++ = rgb[2];

  if (ic->render_to_rgba)
    *line = 0xff;
}

/*
 * Recursively find out the total width and height of the contents of a DLO
 */

void
lws_dlo_contents(lws_dlo_t *parent, lws_dlo_dim_t *dim)
{
  lws_fx_t t1;

  dim->w.whole = 0;
  dim->w.frac = 0;
  dim->h.whole = 0;
  dim->h.frac = 0;

  if (!parent)
    return;

  lws_start_foreach_dll(struct lws_dll2 *, d, lws_dll2_get_head(&parent->children)) {
    lws_dlo_t *child = lws_container_of(d, lws_dlo_t, list);

    lws_fx_add(&t1, &child->box.w, &child->box.x);
    /*
     * Original recursive code added padding here.
     * lws_fx_add(&t1, &t1, &dlo->padding[CCPAS_LEFT]);
     * But box.w usually includes padding in LHP DLOs.
     */
    // lws_fx_add(&t1, &t1, &child->padding[CCPAS_LEFT]);

    if (lws_fx_comp(&t1, &dim->w) > 0)
      dim->w = t1;

    lws_fx_add(&t1, &child->box.h, &child->box.y);
    // lws_fx_add(&t1, &t1, &child->padding[CCPAS_TOP]);

    if (lws_fx_comp(&t1, &dim->h) > 0)
      dim->h = t1;

  } lws_end_foreach_dll(d);

  if (parent->col_list.owner) {
    lhp_table_col_t *tc = lws_container_of(parent->col_list.owner,
          lhp_table_col_t, col_dlos);

    if (lws_fx_comp(&dim->w, &tc->width) < 0) {
  //    lws_fx_add(&t1, &tc->width, &parent->padding[CCPAS_LEFT]);
  //    lws_fx_add(&dim->w, &tc->width, &parent->padding[CCPAS_RIGHT]);
      dim->w = tc->width;
    }
  }

  if (parent->row_list.owner) {
    lhp_table_row_t *tr = lws_container_of(parent->row_list.owner,
          lhp_table_row_t, row_dlos);

    if (lws_fx_comp(&dim->h, &tr->height) < 0) {
  //    lws_fx_add(&t1, &tr->height, &parent->padding[CCPAS_TOP]);
      lws_fx_add(&dim->h, &tr->height, &parent->padding[CCPAS_BOTTOM]);
//      dim->h = tr->height;
    }
  }

/*
  lwsl_user("%s: dlo %p: FINAL w:%d -> %d h:%d -> %d\n", __func__, parent,
      parent->box.w.whole, dim->w.whole,
      parent->box.h.whole, dim->h.whole);
*/
}

/*
 * Some DLO is changing height, adjust its height, and that of everybody below.
 */

void
lws_display_dlo_adjust_dims(lws_dlo_t *dlo, lws_dlo_dim_t *dim)
{
  lws_dlo_dim_t delta;

  if (!dim->w.whole && !dim->h.whole)
    return;

  /* adjust the target's width / height */

  lws_fx_sub(&delta.w, &dim->w, &dlo->box.w);
  lws_fx_sub(&delta.h, &dim->h, &dlo->box.h);

  dlo->box.w = dim->w;
  dlo->box.h = dim->h;

  // lwsl_notice("%s: dlo %p: delta w:%d h:%d\n", __func__, dlo, delta.w.whole, delta.h.whole);

  /* move peers below him accordingly */

  do {
    lws_dlo_t *dp = lws_container_of(dlo->list.owner, lws_dlo_t, children);

    if (!dlo->list.owner)
      break;

    /*
     * Adjust y pos of siblings below us
     */

    do {
      dlo = lws_container_of(dlo->list.next, lws_dlo_t, list);
      if (dlo) {
        //lwsl_notice("%s: dlo %p: adj y %d -> %d\n", __func__, dlo, dlo->box.y.whole, dlo->box.y.whole + delta.h.whole);
        lws_fx_add(&dlo->box.y, &dlo->box.y, &delta.h);
      }
    } while (dlo);


    /* go up parent chain until toplevel adjusting height of
     * parent siblings below parent */

    if (dp->flag_toplevel)
      break;

    dlo = dp;
    //lwsl_notice("%s: dlo %p: adj h by %d\n", __func__, dlo, delta.h.whole);
    lws_fx_add(&dlo->box.h, &dlo->box.h, &delta.h);
  } while (1);
}

//#if defined(_DEBUG)
void
lws_display_dl_dump(lws_displaylist_t *dl)
{
  lws_display_render_stack_t  st[64]; /* DLO child stack */
  int       sp = 0;
  lws_dll2_t *d = lws_dll2_get_head(&dl->dl);
#if (_LWS_ENABLED_LOGS & dlodump_loglevel)
  static const char * const ind = "                           ";
#endif
  char b[4][22], b1[4][22], dt[96];

  if (!d) {
    lwsl_notice("%s: empty dl\n", __func__);

    return;
  }

  lwsl_notice("%s\n", __func__);

  memset(&st, 0, sizeof(st));
  st[0].dlo = lws_container_of(d, lws_dlo_t, list);

  while (sp || st[0].dlo) {
    lws_dlo_t *dlo = st[sp].dlo;
    lws_box_t co;

    if (!dlo) {
      if (!sp) {
        lwsl_err("%s: underflow\n", __func__);
          return;
      }
      sp--;
      continue;
    }

    lws_fx_add(&co.x, &st[sp].co.x, &dlo->box.x);
    lws_fx_add(&co.y, &st[sp].co.y, &dlo->box.y);
    co.w = dlo->box.w;
    co.h = dlo->box.h;

    lws_snprintf(dt, sizeof(dt), "rect: RGBA 0x%08X", (unsigned int)dlo->dc);
    if (dlo->_destroy == lws_display_dlo_text_destroy) {
      lws_dlo_text_t *text = lws_container_of(dlo, lws_dlo_text_t, dlo);
      lws_snprintf(dt, sizeof(dt), "text: RGBA 0x%08X, chars: %u, %.*s",
          (unsigned int)dlo->dc, (unsigned int)text->text_len,
          (int)text->text_len, text->text ? text->text : "(empty)");
    }
#if defined(LWS_WITH_NETWORK) && defined(LWS_WITH_UPNG) && defined(LWS_WITH_CLIENT)
    else if (dlo->_destroy == lws_display_dlo_png_destroy)
      lws_snprintf(dt, sizeof(dt), "png");
#endif
#if defined(LWS_WITH_NETWORK) && defined(LWS_WITH_JPEG) && defined(LWS_WITH_CLIENT)
    else if (dlo->_destroy == lws_display_dlo_jpeg_destroy)
      lws_snprintf(dt, sizeof(dt), "jpeg");
#endif

    lws_fx_string(&dlo->box.x, b[0], sizeof(b[0]));
    lws_fx_string(&dlo->box.y, b[1], sizeof(b[1]));
    lws_fx_string(&dlo->box.w, b[2], sizeof(b[2]));
    lws_fx_string(&dlo->box.h, b[3], sizeof(b[3]));
    lws_fx_string(&co.x, b1[0], sizeof(b1[0]));
    lws_fx_string(&co.y, b1[1], sizeof(b1[1]));
    lws_fx_string(&co.w, b1[2], sizeof(b1[2]));
    lws_fx_string(&co.h, b1[3], sizeof(b1[3]));

    lwsl_dlodump("%.*s %p box: (%s, %s) [%s x %s], co: (%s, %s) [%s x %s], %s\n",
        sp, ind, dlo, b[0], b[1], b[2], b[3],
        b1[0], b1[1], b1[2], b1[3], dt);

    d = dlo->list.next;
    if (d)
      st[sp].dlo = lws_container_of(d, lws_dlo_t, list);
    else
      st[sp].dlo = NULL;

    /* go into any children */

    if (dlo->children.head) {
      if (sp + 1 == LWS_ARRAY_SIZE(st)) {
        lwsl_err("%s: DLO stack overflow\n", __func__);
        return;
      }
      st[++sp].dlo = lws_container_of(
        dlo->children.head, lws_dlo_t, list);
      st[sp].co = co;
    }

  }
}
//#endif

/*
 * Go through every DLO once, setting its id->box to the final layout for the
 * related dlo, if any
 */

lws_stateful_ret_t
lws_display_get_ids_boxes(lws_display_render_state_t *rs)
{
  lws_dll2_t *d;

  rs->lowest_id_y = 0;

  d = lws_dll2_get_head(&rs->displaylist.dl);
  if (!d)
    /* nothing in dlo */
    return LWS_SRET_OK;

  memset(&rs->st[0].co, 0, sizeof(rs->st[0].co));
  rs->st[0].dlo = lws_container_of(d, lws_dlo_t, list);

  while (rs->sp || rs->st[0].dlo) {
    lws_dlo_t *dlo = rs->st[rs->sp].dlo;
    lws_box_t co;
    lws_fx_t t2;

    if (!dlo) {
      rs->sp--;
      continue;
    }

    lws_fx_add(&co.x, &rs->st[rs->sp].co.x, &dlo->box.x);
    lws_fx_add(&co.y, &rs->st[rs->sp].co.y, &dlo->box.y);
    co.w = dlo->box.w;
    co.h = dlo->box.h;

    lws_fx_add(&t2, &co.y, &dlo->box.h);


    if (dlo->id) {
      lws_display_id_t *id = dlo->id;

      if (id) {
        id->id[sizeof(id->id) - 1] = '\0';
        lwsl_debug("%s: set id box %s\n", __func__, id->id);

        id->box = co;
      }
      dlo->id = NULL; /* decouple us */
    }


    if (co.y.whole + co.h.whole > rs->lowest_id_y) {
      rs->lowest_id_y = (lws_display_scalar)(co.y.whole + co.h.whole);
      if (rs->lowest_id_y > rs->ic->wh_px[1].whole)
        rs->lowest_id_y = (lws_display_scalar)rs->ic->wh_px[1].whole;
    }

    /* next sibling at this level if any */

    d = dlo->list.next;
    if (d)
      rs->st[rs->sp].dlo = lws_container_of(d,
            lws_dlo_t, list);
    else
      rs->st[rs->sp].dlo = NULL;

    /* go into any children */

    if (dlo->children.head) {
      if (rs->sp + 1 == LWS_ARRAY_SIZE(rs->st)) {
        lwsl_err("%s: DLO stack overflow A\n",
            __func__);
        return LWS_SRET_FATAL;
      }
      rs->st[++rs->sp].dlo = lws_container_of(
        dlo->children.head, lws_dlo_t, list);
      rs->st[rs->sp].co = co;
      continue;
    }
  }

  lws_display_render_dump_ids(&rs->ids);

  return LWS_SRET_OK;
}

lws_stateful_ret_t
lws_display_list_render_line(lws_display_render_state_t *rs)
{
  lws_dll2_t *d;

  if (rs->html == 1) {
    lwsl_notice("%s: returning LWS_SRET_WANT_INPUT due to rs->html = 1\n", __func__);
    return LWS_SRET_WANT_INPUT;
  }

  if (!rs->sp && !rs->st[0].dlo) {

    /* starting a line */

    d = lws_dll2_get_head(&rs->displaylist.dl);
    if (!d)
      /* nothing in dlo */
      return LWS_SRET_OK;

  //  memset(rs->line, 0, (size_t)rs->ic->wh_px[0].whole *
  //        (rs->ic->greyscale ? 1 : 3));
    memset(&rs->st[0].co, 0, sizeof(rs->st[0].co));
    rs->st[0].dlo = lws_container_of(d, lws_dlo_t, list);
  }

  while (rs->sp || rs->st[0].dlo) {
    lws_dlo_t *dlo = rs->st[rs->sp].dlo;
    lws_stateful_ret_t r;
    lws_box_t co;
    lws_fx_t t2;

    if (!dlo) {
      rs->sp--;
      continue;
    }

//    lwsl_notice("%s: curr %d: %d %d %d %d\n", __func__, (int)rs->curr, (int)dlo->box.x.whole, (int)dlo->box.y.whole, (int)dlo->box.w.whole, (int)dlo->box.h.whole);

    lws_fx_add(&co.x, &rs->st[rs->sp].co.x, &dlo->box.x);
    lws_fx_add(&co.y, &rs->st[rs->sp].co.y, &dlo->box.y);

    co.w = dlo->box.w;
    co.h = dlo->box.h;

    lws_fx_add(&t2, &co.y, &dlo->box.h);

    if (rs->curr > lws_fx_roundup(&t2) && dlo->box.h.whole > 3) {
      d = dlo->list.next;
      rs->st[rs->sp].dlo = d ? lws_container_of(d, lws_dlo_t,
                list) : NULL;

      lws_display_dlo_destroy(&dlo);
      continue;
    }

#if 0
    if (dlo->_destroy == lws_display_dlo_png_destroy)
      lwsl_err("png line %d %d %d %d\n", rs->curr, co.y.whole - 1,
          rs->st[rs->sp].co.y.whole, dlo->box.y.whole);
#endif

    if (rs->curr >= co.y.whole - 1) {

      r = dlo->render(rs);

      //rs->ic, dlo, &rs->st[rs->sp].co,
      //    rs->curr, rs->line, &dlo->nle[0]);
      if (r)
        return r;

      /* next sibling at this level if any */

      d = dlo->list.next;

      if (d)
        rs->st[rs->sp].dlo = lws_container_of(d,
              lws_dlo_t, list);
      else
        rs->st[rs->sp].dlo = NULL;


      /* go into any children */

      if (dlo->children.head) {
        if (rs->sp + 1 == LWS_ARRAY_SIZE(rs->st)) {
          lwsl_err("%s: DLO stack overflow B\n",
              __func__);
          return LWS_SRET_FATAL;
        }
        rs->st[++rs->sp].dlo = lws_container_of(
          dlo->children.head, lws_dlo_t, list);
        rs->st[rs->sp].co = co;
        continue;
      }
    } else {
      /* next sibling at this level if any */

      d = dlo->list.next;
      if (d)
        rs->st[rs->sp].dlo = lws_container_of(d,
              lws_dlo_t, list);
      else
        rs->st[rs->sp].dlo = NULL;
    }


  }

  return LWS_SRET_OK;
}

static int
dlo_clean_table_rows(lws_dll2_t *d, void *user)
{
  lhp_table_row_t *r = lws_container_of(d, lhp_table_row_t, list);

  lws_dll2_remove(d);
  lws_free(r);

  return 0;
}

static int
dlo_clean_table_cols(lws_dll2_t *d, void *user)
{
  lhp_table_col_t *c = lws_container_of(d, lhp_table_col_t, list);

  lws_dll2_remove(d);
  lws_free(c);

  return 0;
}

void
lws_display_dlo_destroy(lws_dlo_t **r)
{
  lws_dlo_t *rr = *r;

  if (!rr)
    return;

  lws_dll2_remove(&rr->list);
  lws_dll2_remove(&rr->col_list);
  lws_dll2_remove(&rr->row_list);

  while (rr->children.head) {
    lws_dlo_t *d = lws_container_of(rr->children.head,
              lws_dlo_t, list);

    lws_display_dlo_destroy(&d);
  }

  lws_dll2_foreach_safe(&rr->table_cols, NULL, dlo_clean_table_cols);
  lws_dll2_foreach_safe(&rr->table_rows, NULL, dlo_clean_table_rows);

  if (rr->_destroy)
    rr->_destroy(rr);

  lws_free_set_NULL(*r);
}

void
lws_display_list_destroy(struct lws_context *cx, lws_displaylist_t *dl)
{
  if (!dl)
    return;

  //lws_dlo_ss_stop_any_active(cx);

  while (dl->dl.head) {
    lws_dlo_t *d = lws_container_of(dl->dl.head, lws_dlo_t, list);

    lws_display_dlo_destroy(&d);
  }
}

lws_dlo_filesystem_t *
lws_dlo_file_register(struct lws_context *cx, const lws_dlo_filesystem_t *f)
{
  const lws_dlo_filesystem_t *b;
  lws_dlo_filesystem_t *a;

  b = lws_dlo_file_choose(cx, f->name);

  if (b) {
    lwsl_err("%s: dlo file %s already exists %p\n", __func__, b->name, b);
    lws_dlo_file_unregister((lws_dlo_filesystem_t **)&b);
  }

  a = lws_malloc(sizeof(*a), __func__);
  if (!a)
    return NULL;

  *a = *f;
  lws_dll2_clear(&a->list);
  lws_dll2_add_tail(&a->list, &cx->dlo_file);

  lwsl_err("%s: dlo file %s registered at %p\n", __func__, a->name, a);

  return a;
}

/*
 * Only needed with heap-alloc'd lws_dlo_filesystem_t
 */

void
lws_dlo_file_unregister(lws_dlo_filesystem_t **f)
{
  if (!*f)
    return;

  lws_dll2_remove(&(*f)->list);
  lws_free_set_NULL(*f);
}

void
lws_dlo_file_unregister_by_name(struct lws_context *cx, const char *name)
{
  lws_dlo_filesystem_t *a;

  a = (lws_dlo_filesystem_t *)lws_dlo_file_choose(cx, name);
  if (!a)
    return;

  lws_dll2_remove(&a->list);
  lws_free_set_NULL(a);
}

static int
_lws_dlo_file_destroy(struct lws_dll2 *d, void *user)
{
  lws_free(d);
  return 0;
}

void
lws_dlo_file_destroy(struct lws_context *cx)
{
  lws_dll2_foreach_safe(&cx->dlo_file, NULL, _lws_dlo_file_destroy);
}

const lws_dlo_filesystem_t *
lws_dlo_file_choose(struct lws_context *cx, const char *name)
{
  lws_start_foreach_dll(struct lws_dll2 *, p,
            lws_dll2_get_head(&cx->dlo_file)) {
    const lws_dlo_filesystem_t *pn = lws_container_of(p,
            lws_dlo_filesystem_t, list);

    if (!strcmp(name, pn->name))
      return pn;

  } lws_end_foreach_dll(p);

  return NULL;
}

static int
lws_display_id_destroy(struct lws_dll2 *d, void *user)
{
  lws_display_id_t *id = lws_container_of(d, lws_display_id_t, list);

  lws_dll2_remove(&id->list);
  lws_free(id);
  return 0;
}

void
lws_display_render_free_ids(lws_display_render_state_t *rs)
{
  lws_dll2_foreach_safe(&rs->ids, NULL, lws_display_id_destroy);
}

lws_display_id_t *
lws_display_render_get_id(lws_display_render_state_t *rs, const char *_id)
{
  lws_start_foreach_dll(struct lws_dll2 *, d, lws_dll2_get_head(&rs->ids)) {
    lws_display_id_t *id = lws_container_of(d, lws_display_id_t, list);

    if (!strcmp(_id, id->id))
      return id;

  } lws_end_foreach_dll(d);

  return NULL;
}

lws_display_id_t *
lws_display_render_add_id(lws_display_render_state_t *rs, const char *_id, void *priv)
{
  lws_display_id_t *id;

  id = lws_display_render_get_id(rs, _id);
  if (id) {
    id->priv_user = priv;
    return id;
  }

  id = lws_zalloc(sizeof(*id), __func__);

  if (id) {
    lws_strncpy(id->id, _id, sizeof(id->id));
    id->priv_user = priv;
    lws_dll2_add_tail(&id->list, &rs->ids);
  }

  return id;
}

void
lws_display_render_dump_ids(lws_dll2_owner_t *ids)
{
  lws_start_foreach_dll(struct lws_dll2 *, d, lws_dll2_get_head(ids)) {
    lws_display_id_t *id = lws_container_of(d, lws_display_id_t, list);

    if (!id->exists)
      lwsl_notice("  id: '%s' (not present)\n", id->id);
    else
      lwsl_notice("  id: '%s', (%d,%d), %dx%d\n", id->id,
          (int)id->box.x.whole, (int)id->box.y.whole,
          (int)id->box.w.whole, (int)id->box.h.whole);
  } lws_end_foreach_dll(d);
}

#if defined (LWS_WITH_FILE_OPS)

int
dlo_filesystem_fops_close(lws_fop_fd_t *fop_fd)
{
  lws_free_set_NULL(*fop_fd);
  return 0;
}

lws_fileofs_t
dlo_filesystem_fops_seek_cur(lws_fop_fd_t fop_fd,
           lws_fileofs_t pos)
{
  if (pos < 0)
    fop_fd->pos = 0;
  else
    if (pos >= (long long)fop_fd->len)
      fop_fd->pos = fop_fd->len;
    else
      fop_fd->pos = (lws_filepos_t)pos;

  return (lws_fileofs_t)fop_fd->pos;
}

int
dlo_filesystem_fops_write(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
        uint8_t *buf, lws_filepos_t len)
{
  *amount = 0;

  return -1;
}

int
dlo_filesystem_fops_read(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
        uint8_t *buf, lws_filepos_t len)
{
  const uint8_t *p = (uint8_t *)fop_fd->filesystem_priv;
  lws_filepos_t amt = *amount;

  *amount = 0;
  if (fop_fd->len <= fop_fd->pos)
    return 0;

  if (amt > fop_fd->len - fop_fd->pos)
    amt = fop_fd->len - fop_fd->pos;

  if (amt > len)
    amt = len;

  memcpy(buf, p + fop_fd->pos, (size_t)amt);
  fop_fd->pos += amt;

  *amount = amt;

  return 0;
}

lws_fop_fd_t
lws_dlo_filesystem_fops_open(const struct lws_plat_file_ops *fops_own,
           const struct lws_plat_file_ops *fops,
           const char *vfs_path, const char *vpath,
           lws_fop_flags_t *flags)
{
  const lws_dlo_filesystem_t *f = NULL;
  lws_fop_fd_t fop_fd;

  // lwsl_err("%s: %s\n", __func__, vpath);

  f = lws_dlo_file_choose(fops->cx, vpath);
  if (f) {
    /* we will handle it then */
    fop_fd = lws_zalloc(sizeof(*fop_fd), __func__);
    if (!fop_fd)
      return NULL;

    fop_fd->fops = fops_own;
    fop_fd->filesystem_priv = (void *)f->data;
    fop_fd->pos = 0;
    fop_fd->len = f->len;

    // lwsl_notice("%s: Opened %s\n", __func__, vpath);

    return fop_fd;
  } else
    lwsl_err("%s: failed to open %s\n", __func__, vpath);

  return NULL;
}

const struct lws_plat_file_ops lws_dlo_fops = {
  .LWS_FOP_OPEN   = lws_dlo_filesystem_fops_open,
  .LWS_FOP_CLOSE    = dlo_filesystem_fops_close,
  .LWS_FOP_SEEK_CUR = dlo_filesystem_fops_seek_cur,
  .LWS_FOP_READ   = dlo_filesystem_fops_read,
  .LWS_FOP_WRITE    = dlo_filesystem_fops_write,
  .fi = { { "dlofs/", 6 } },
};

#endif

Coverage Report

Created: 2026-02-14 07:00