/src/git/reftable/writer.c

Source
/*
 * Copyright 2020 Google LLC
 *
 * Use of this source code is governed by a BSD-style
 * license that can be found in the LICENSE file or at
 * https://developers.google.com/open-source/licenses/bsd
 */

#include "writer.h"

#include "system.h"

#include "block.h"
#include "constants.h"
#include "record.h"
#include "tree.h"
#include "reftable-error.h"

/* finishes a block, and writes it to storage */
static int writer_flush_block(struct reftable_writer *w);

/* deallocates memory related to the index */
static void writer_clear_index(struct reftable_writer *w);

/* finishes writing a 'r' (refs) or 'g' (reflogs) section */
static int writer_finish_public_section(struct reftable_writer *w);

static struct reftable_block_stats *
writer_reftable_block_stats(struct reftable_writer *w, uint8_t typ)
{
  switch (typ) {
  case 'r':
    return &w->stats.ref_stats;
  case 'o':
    return &w->stats.obj_stats;
  case 'i':
    return &w->stats.idx_stats;
  case 'g':
    return &w->stats.log_stats;
  }
  abort();
  return NULL;
}

/* write data, queuing the padding for the next write. Returns negative for
 * error. */
static int padded_write(struct reftable_writer *w, uint8_t *data, size_t len,
      int padding)
{
  int n = 0;
  if (w->pending_padding > 0) {
    uint8_t *zeroed;
    int n;

    zeroed = reftable_calloc(w->pending_padding, sizeof(*zeroed));
    if (!zeroed)
      return -1;

    n = w->write(w->write_arg, zeroed, w->pending_padding);
    if (n < 0) {
      reftable_free(zeroed);
      return n;
    }

    w->pending_padding = 0;
    reftable_free(zeroed);
  }

  w->pending_padding = padding;
  n = w->write(w->write_arg, data, len);
  if (n < 0)
    return n;
  n += padding;
  return 0;
}

static void options_set_defaults(struct reftable_write_options *opts)
{
  if (opts->restart_interval == 0) {
    opts->restart_interval = 16;
  }

  if (opts->hash_id == 0) {
    opts->hash_id = REFTABLE_HASH_SHA1;
  }
  if (opts->block_size == 0) {
    opts->block_size = DEFAULT_BLOCK_SIZE;
  }
}

static int writer_version(struct reftable_writer *w)
{
  return (w->opts.hash_id == 0 || w->opts.hash_id == REFTABLE_HASH_SHA1) ?
           1 :
           2;
}

static int writer_write_header(struct reftable_writer *w, uint8_t *dest)
{
  memcpy(dest, "REFT", 4);

  dest[4] = writer_version(w);

  reftable_put_be24(dest + 5, w->opts.block_size);
  reftable_put_be64(dest + 8, w->min_update_index);
  reftable_put_be64(dest + 16, w->max_update_index);
  if (writer_version(w) == 2) {
    uint32_t hash_id;

    switch (w->opts.hash_id) {
    case REFTABLE_HASH_SHA1:
      hash_id = REFTABLE_FORMAT_ID_SHA1;
      break;
    case REFTABLE_HASH_SHA256:
      hash_id = REFTABLE_FORMAT_ID_SHA256;
      break;
    default:
      return -1;
    }

    reftable_put_be32(dest + 24, hash_id);
  }

  return header_size(writer_version(w));
}

static int writer_reinit_block_writer(struct reftable_writer *w, uint8_t typ)
{
  int block_start = 0, ret;

  if (w->next == 0)
    block_start = header_size(writer_version(w));

  reftable_buf_reset(&w->last_key);
  ret = block_writer_init(&w->block_writer_data, typ, w->block,
        w->opts.block_size, block_start,
        hash_size(w->opts.hash_id));
  if (ret < 0)
    return ret;

  w->block_writer = &w->block_writer_data;
  w->block_writer->restart_interval = w->opts.restart_interval;

  return 0;
}

int reftable_writer_new(struct reftable_writer **out,
      ssize_t (*writer_func)(void *, const void *, size_t),
      int (*flush_func)(void *),
      void *writer_arg, const struct reftable_write_options *_opts)
{
  struct reftable_write_options opts = {0};
  struct reftable_writer *wp;

  wp = reftable_calloc(1, sizeof(*wp));
  if (!wp)
    return REFTABLE_OUT_OF_MEMORY_ERROR;

  if (_opts)
    opts = *_opts;
  options_set_defaults(&opts);
  if (opts.block_size >= (1 << 24))
    return REFTABLE_API_ERROR;

  reftable_buf_init(&wp->block_writer_data.last_key);
  reftable_buf_init(&wp->last_key);
  reftable_buf_init(&wp->scratch);
  REFTABLE_CALLOC_ARRAY(wp->block, opts.block_size);
  if (!wp->block) {
    reftable_free(wp);
    return REFTABLE_OUT_OF_MEMORY_ERROR;
  }
  wp->write = writer_func;
  wp->write_arg = writer_arg;
  wp->opts = opts;
  wp->flush = flush_func;
  writer_reinit_block_writer(wp, REFTABLE_BLOCK_TYPE_REF);

  *out = wp;

  return 0;
}

int reftable_writer_set_limits(struct reftable_writer *w, uint64_t min,
        uint64_t max)
{
  /*
    * Set the min/max update index limits for the reftable writer.
    * This must be called before adding any records, since:
    * - The 'next' field gets set after writing the first block.
    * - The 'last_key' field updates with each new record (but resets
    *   after sections).
    * Returns REFTABLE_API_ERROR if called after writing has begun.
   */
  if (w->next || w->last_key.len)
    return REFTABLE_API_ERROR;

  w->min_update_index = min;
  w->max_update_index = max;

  return 0;
}

static void writer_release(struct reftable_writer *w)
{
  if (w) {
    reftable_free(w->block);
    w->block = NULL;
    block_writer_release(&w->block_writer_data);
    w->block_writer = NULL;
    writer_clear_index(w);
    reftable_buf_release(&w->last_key);
    reftable_buf_release(&w->scratch);
  }
}

void reftable_writer_free(struct reftable_writer *w)
{
  writer_release(w);
  reftable_free(w);
}

struct obj_index_tree_node {
  struct reftable_buf hash;
  uint64_t *offsets;
  size_t offset_len;
  size_t offset_cap;
};

#define OBJ_INDEX_TREE_NODE_INIT    \
  {                           \
    .hash = REFTABLE_BUF_INIT \
  }

static int obj_index_tree_node_compare(const void *a, const void *b)
{
  return reftable_buf_cmp(&((const struct obj_index_tree_node *)a)->hash,
        &((const struct obj_index_tree_node *)b)->hash);
}

static int writer_index_hash(struct reftable_writer *w, struct reftable_buf *hash)
{
  uint64_t off = w->next;
  struct obj_index_tree_node want = { .hash = *hash };
  struct obj_index_tree_node *key;
  struct tree_node *node;

  node = tree_search(w->obj_index_tree, &want, &obj_index_tree_node_compare);
  if (!node) {
    struct obj_index_tree_node empty = OBJ_INDEX_TREE_NODE_INIT;
    int err;

    key = reftable_malloc(sizeof(*key));
    if (!key)
      return REFTABLE_OUT_OF_MEMORY_ERROR;

    *key = empty;

    reftable_buf_reset(&key->hash);
    err = reftable_buf_add(&key->hash, hash->buf, hash->len);
    if (err < 0) {
      reftable_free(key);
      return err;
    }
    tree_insert(&w->obj_index_tree, key,
          &obj_index_tree_node_compare);
  } else {
    key = node->key;
  }

  if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off)
    return 0;

  REFTABLE_ALLOC_GROW_OR_NULL(key->offsets, key->offset_len + 1,
            key->offset_cap);
  if (!key->offsets)
    return REFTABLE_OUT_OF_MEMORY_ERROR;
  key->offsets[key->offset_len++] = off;

  return 0;
}

static int writer_add_record(struct reftable_writer *w,
           struct reftable_record *rec)
{
  int err;

  err = reftable_record_key(rec, &w->scratch);
  if (err < 0)
    goto done;

  if (reftable_buf_cmp(&w->last_key, &w->scratch) >= 0) {
    err = REFTABLE_API_ERROR;
    goto done;
  }

  reftable_buf_reset(&w->last_key);
  err = reftable_buf_add(&w->last_key, w->scratch.buf, w->scratch.len);
  if (err < 0)
    goto done;

  if (!w->block_writer) {
    err = writer_reinit_block_writer(w, reftable_record_type(rec));
    if (err < 0)
      goto done;
  }

  if (block_writer_type(w->block_writer) != reftable_record_type(rec))
    return REFTABLE_API_ERROR;

  /*
   * Try to add the record to the writer. If this succeeds then we're
   * done. Otherwise the block writer may have hit the block size limit
   * and needs to be flushed.
   */
  err = block_writer_add(w->block_writer, rec);
  if (err == 0)
    goto done;

  if (err != REFTABLE_ENTRY_TOO_BIG_ERROR)
    goto done;
  /*
   * The current block is full, so we need to flush and reinitialize the
   * writer to start writing the next block.
   */
  err = writer_flush_block(w);
  if (err < 0)
    goto done;
  err = writer_reinit_block_writer(w, reftable_record_type(rec));
  if (err < 0)
    goto done;

  /*
   * Try to add the record to the writer again. If this still fails then
   * the record does not fit into the block size.
   */
  err = block_writer_add(w->block_writer, rec);
  if (err)
    goto done;

done:
  return err;
}

int reftable_writer_add_ref(struct reftable_writer *w,
          struct reftable_ref_record *ref)
{
  struct reftable_record rec = {
    .type = REFTABLE_BLOCK_TYPE_REF,
    .u = {
      .ref = *ref
    },
  };
  int err;

  if (!ref->refname ||
      ref->update_index < w->min_update_index ||
      ref->update_index > w->max_update_index)
    return REFTABLE_API_ERROR;

  rec.u.ref.update_index -= w->min_update_index;

  err = writer_add_record(w, &rec);
  if (err < 0)
    goto out;

  if (!w->opts.skip_index_objects && reftable_ref_record_val1(ref)) {
    reftable_buf_reset(&w->scratch);
    err = reftable_buf_add(&w->scratch, (char *)reftable_ref_record_val1(ref),
               hash_size(w->opts.hash_id));
    if (err < 0)
      goto out;

    err = writer_index_hash(w, &w->scratch);
    if (err < 0)
      goto out;
  }

  if (!w->opts.skip_index_objects && reftable_ref_record_val2(ref)) {
    reftable_buf_reset(&w->scratch);
    err = reftable_buf_add(&w->scratch, reftable_ref_record_val2(ref),
               hash_size(w->opts.hash_id));
    if (err < 0)
      goto out;

    err = writer_index_hash(w, &w->scratch);
    if (err < 0)
      goto out;
  }

  err = 0;

out:
  return err;
}

int reftable_writer_add_refs(struct reftable_writer *w,
           struct reftable_ref_record *refs, size_t n)
{
  int err = 0;

  if (n)
    qsort(refs, n, sizeof(*refs), reftable_ref_record_compare_name);

  for (size_t i = 0; err == 0 && i < n; i++)
    err = reftable_writer_add_ref(w, &refs[i]);

  return err;
}

static int reftable_writer_add_log_verbatim(struct reftable_writer *w,
              struct reftable_log_record *log)
{
  struct reftable_record rec = {
    .type = REFTABLE_BLOCK_TYPE_LOG,
    .u = {
      .log = *log,
    },
  };
  if (w->block_writer &&
      block_writer_type(w->block_writer) == REFTABLE_BLOCK_TYPE_REF) {
    int err = writer_finish_public_section(w);
    if (err < 0)
      return err;
  }

  w->next -= w->pending_padding;
  w->pending_padding = 0;
  return writer_add_record(w, &rec);
}

int reftable_writer_add_log(struct reftable_writer *w,
          struct reftable_log_record *log)
{
  char *input_log_message = NULL;
  struct reftable_buf cleaned_message = REFTABLE_BUF_INIT;
  int err = 0;

  if (log->value_type == REFTABLE_LOG_DELETION)
    return reftable_writer_add_log_verbatim(w, log);

  /*
   * Verify only the upper limit of the update_index. Each reflog entry
   * is tied to a specific update_index. Entries in the reflog can be
   * replaced by adding a new entry with the same update_index,
   * effectively canceling the old one.
   *
   * Consequently, reflog updates may include update_index values lower
   * than the writer's min_update_index.
   */
  if (log->update_index > w->max_update_index)
    return REFTABLE_API_ERROR;

  if (!log->refname)
    return REFTABLE_API_ERROR;

  input_log_message = log->value.update.message;
  if (!w->opts.exact_log_message && log->value.update.message) {
    err = reftable_buf_addstr(&cleaned_message, log->value.update.message);
    if (err < 0)
      goto done;

    while (cleaned_message.len &&
           cleaned_message.buf[cleaned_message.len - 1] == '\n') {
      err = reftable_buf_setlen(&cleaned_message,
              cleaned_message.len - 1);
      if (err < 0)
        goto done;
    }
    if (strchr(cleaned_message.buf, '\n')) {
      /* multiple lines not allowed. */
      err = REFTABLE_API_ERROR;
      goto done;
    }

    err = reftable_buf_addstr(&cleaned_message, "\n");
    if (err < 0)
      goto done;

    log->value.update.message = cleaned_message.buf;
  }

  err = reftable_writer_add_log_verbatim(w, log);
  log->value.update.message = input_log_message;
done:
  reftable_buf_release(&cleaned_message);
  return err;
}

int reftable_writer_add_logs(struct reftable_writer *w,
           struct reftable_log_record *logs, size_t n)
{
  int err = 0;

  if (n)
    qsort(logs, n, sizeof(*logs), reftable_log_record_compare_key);

  for (size_t i = 0; err == 0 && i < n; i++)
    err = reftable_writer_add_log(w, &logs[i]);

  return err;
}

static int writer_finish_section(struct reftable_writer *w)
{
  struct reftable_block_stats *bstats = NULL;
  uint8_t typ = block_writer_type(w->block_writer);
  uint64_t index_start = 0;
  int max_level = 0;
  size_t threshold = w->opts.unpadded ? 1 : 3;
  int before_blocks = w->stats.idx_stats.blocks;
  int err;

  err = writer_flush_block(w);
  if (err < 0)
    return err;

  /*
   * When the section we are about to index has a lot of blocks then the
   * index itself may span across multiple blocks, as well. This would
   * require a linear scan over index blocks only to find the desired
   * indexed block, which is inefficient. Instead, we write a multi-level
   * index where index records of level N+1 will refer to index blocks of
   * level N. This isn't constant time, either, but at least logarithmic.
   *
   * This loop handles writing this multi-level index. Note that we write
   * the lowest-level index pointing to the indexed blocks first. We then
   * continue writing additional index levels until the current level has
   * less blocks than the threshold so that the highest level will be at
   * the end of the index section.
   *
   * Readers are thus required to start reading the index section from
   * its end, which is why we set `index_start` to the beginning of the
   * last index section.
   */
  while (w->index_len > threshold) {
    struct reftable_index_record *idx = NULL;
    size_t i, idx_len;

    max_level++;
    index_start = w->next;
    err = writer_reinit_block_writer(w, REFTABLE_BLOCK_TYPE_INDEX);
    if (err < 0)
      return err;

    idx = w->index;
    idx_len = w->index_len;

    w->index = NULL;
    w->index_len = 0;
    w->index_cap = 0;
    for (i = 0; i < idx_len; i++) {
      struct reftable_record rec = {
        .type = REFTABLE_BLOCK_TYPE_INDEX,
        .u = {
          .idx = idx[i],
        },
      };

      err = writer_add_record(w, &rec);
      if (err < 0)
        return err;
    }

    err = writer_flush_block(w);
    if (err < 0)
      return err;

    for (i = 0; i < idx_len; i++)
      reftable_buf_release(&idx[i].last_key);
    reftable_free(idx);
  }

  /*
   * The index may still contain a number of index blocks lower than the
   * threshold. Clear it so that these entries don't leak into the next
   * index section.
   */
  writer_clear_index(w);

  bstats = writer_reftable_block_stats(w, typ);
  bstats->index_blocks = w->stats.idx_stats.blocks - before_blocks;
  bstats->index_offset = index_start;
  bstats->max_index_level = max_level;

  /* Reinit lastKey, as the next section can start with any key. */
  reftable_buf_reset(&w->last_key);

  return 0;
}

struct common_prefix_arg {
  struct reftable_buf *last;
  size_t max;
};

static void update_common(void *void_arg, void *key)
{
  struct common_prefix_arg *arg = void_arg;
  struct obj_index_tree_node *entry = key;
  if (arg->last) {
    size_t n = common_prefix_size(&entry->hash, arg->last);
    if (n > arg->max)
      arg->max = n;
  }
  arg->last = &entry->hash;
}

struct write_record_arg {
  struct reftable_writer *w;
  int err;
};

static void write_object_record(void *void_arg, void *key)
{
  struct write_record_arg *arg = void_arg;
  struct obj_index_tree_node *entry = key;
  struct reftable_record
    rec = { .type = REFTABLE_BLOCK_TYPE_OBJ,
      .u.obj = {
        .hash_prefix = (uint8_t *)entry->hash.buf,
        .hash_prefix_len = arg->w->stats.object_id_len,
        .offsets = entry->offsets,
        .offset_len = entry->offset_len,
      } };
  if (arg->err < 0)
    goto done;

  /*
   * Try to add the record to the writer. If this succeeds then we're
   * done. Otherwise the block writer may have hit the block size limit
   * and needs to be flushed.
   */
  arg->err = block_writer_add(arg->w->block_writer, &rec);
  if (arg->err == 0)
    goto done;

  if (arg->err != REFTABLE_ENTRY_TOO_BIG_ERROR)
    goto done;

  /*
   * The current block is full, so we need to flush and reinitialize the
   * writer to start writing the next block.
   */
  arg->err = writer_flush_block(arg->w);
  if (arg->err < 0)
    goto done;

  arg->err = writer_reinit_block_writer(arg->w, REFTABLE_BLOCK_TYPE_OBJ);
  if (arg->err < 0)
    goto done;

  /*
   * If this still fails then we may need to reset record's offset
   * length to reduce the data size to be written.
   */
  arg->err = block_writer_add(arg->w->block_writer, &rec);
  if (arg->err == 0)
    goto done;

  if (arg->err != REFTABLE_ENTRY_TOO_BIG_ERROR)
    goto done;

  rec.u.obj.offset_len = 0;
  arg->err = block_writer_add(arg->w->block_writer, &rec);

  /* Should be able to write into a fresh block. */
  assert(arg->err == 0);

done:;
}

static void object_record_free(void *void_arg REFTABLE_UNUSED, void *key)
{
  struct obj_index_tree_node *entry = key;

  REFTABLE_FREE_AND_NULL(entry->offsets);
  reftable_buf_release(&entry->hash);
  reftable_free(entry);
}

static int writer_dump_object_index(struct reftable_writer *w)
{
  struct write_record_arg closure = { .w = w };
  struct common_prefix_arg common = {
    .max = 1,   /* obj_id_len should be >= 2. */
  };
  int err;

  if (w->obj_index_tree)
    infix_walk(w->obj_index_tree, &update_common, &common);
  w->stats.object_id_len = common.max + 1;

  err = writer_reinit_block_writer(w, REFTABLE_BLOCK_TYPE_OBJ);
  if (err < 0)
    return err;

  if (w->obj_index_tree)
    infix_walk(w->obj_index_tree, &write_object_record, &closure);

  if (closure.err < 0)
    return closure.err;
  return writer_finish_section(w);
}

static int writer_finish_public_section(struct reftable_writer *w)
{
  uint8_t typ = 0;
  int err = 0;

  if (!w->block_writer)
    return 0;

  typ = block_writer_type(w->block_writer);
  err = writer_finish_section(w);
  if (err < 0)
    return err;
  if (typ == REFTABLE_BLOCK_TYPE_REF && !w->opts.skip_index_objects &&
      w->stats.ref_stats.index_blocks > 0) {
    err = writer_dump_object_index(w);
    if (err < 0)
      return err;
  }

  if (w->obj_index_tree) {
    infix_walk(w->obj_index_tree, &object_record_free, NULL);
    tree_free(w->obj_index_tree);
    w->obj_index_tree = NULL;
  }

  w->block_writer = NULL;
  return 0;
}

int reftable_writer_close(struct reftable_writer *w)
{
  uint8_t footer[72];
  uint8_t *p = footer;
  int err = writer_finish_public_section(w);
  int empty_table = w->next == 0;
  if (err != 0)
    goto done;
  w->pending_padding = 0;
  if (empty_table) {
    /* Empty tables need a header anyway. */
    uint8_t header[28];
    int n = writer_write_header(w, header);
    err = padded_write(w, header, n, 0);
    if (err < 0)
      goto done;
  }

  p += writer_write_header(w, footer);
  reftable_put_be64(p, w->stats.ref_stats.index_offset);
  p += 8;
  reftable_put_be64(p, (w->stats.obj_stats.offset) << 5 | w->stats.object_id_len);
  p += 8;
  reftable_put_be64(p, w->stats.obj_stats.index_offset);
  p += 8;

  reftable_put_be64(p, w->stats.log_stats.offset);
  p += 8;
  reftable_put_be64(p, w->stats.log_stats.index_offset);
  p += 8;

  reftable_put_be32(p, crc32(0, footer, p - footer));
  p += 4;

  err = w->flush(w->write_arg);
  if (err < 0) {
    err = REFTABLE_IO_ERROR;
    goto done;
  }

  err = padded_write(w, footer, footer_size(writer_version(w)), 0);
  if (err < 0)
    goto done;

  if (empty_table) {
    err = REFTABLE_EMPTY_TABLE_ERROR;
    goto done;
  }

done:
  writer_release(w);
  return err;
}

static void writer_clear_index(struct reftable_writer *w)
{
  for (size_t i = 0; w->index && i < w->index_len; i++)
    reftable_buf_release(&w->index[i].last_key);
  REFTABLE_FREE_AND_NULL(w->index);
  w->index_len = 0;
  w->index_cap = 0;
}

static int writer_flush_nonempty_block(struct reftable_writer *w)
{
  struct reftable_index_record index_record = {
    .last_key = REFTABLE_BUF_INIT,
  };
  uint8_t typ = block_writer_type(w->block_writer);
  struct reftable_block_stats *bstats;
  int raw_bytes, padding = 0, err;
  uint64_t block_typ_off;

  /*
   * Finish the current block. This will cause the block writer to emit
   * restart points and potentially compress records in case we are
   * writing a log block.
   *
   * Note that this is still happening in memory.
   */
  raw_bytes = block_writer_finish(w->block_writer);
  if (raw_bytes < 0)
    return raw_bytes;

  /*
   * By default, all records except for log records are padded to the
   * block size.
   */
  if (!w->opts.unpadded && typ != REFTABLE_BLOCK_TYPE_LOG)
    padding = w->opts.block_size - raw_bytes;

  bstats = writer_reftable_block_stats(w, typ);
  block_typ_off = (bstats->blocks == 0) ? w->next : 0;
  if (block_typ_off > 0)
    bstats->offset = block_typ_off;
  bstats->entries += w->block_writer->entries;
  bstats->restarts += w->block_writer->restart_len;
  bstats->blocks++;
  w->stats.blocks++;

  /*
   * If this is the first block we're writing to the table then we need
   * to also write the reftable header.
   */
  if (!w->next)
    writer_write_header(w, w->block);

  err = padded_write(w, w->block, raw_bytes, padding);
  if (err < 0)
    return err;

  /*
   * Add an index record for every block that we're writing. If we end up
   * having more than a threshold of index records we will end up writing
   * an index section in `writer_finish_section()`. Each index record
   * contains the last record key of the block it is indexing as well as
   * the offset of that block.
   *
   * Note that this also applies when flushing index blocks, in which
   * case we will end up with a multi-level index.
   */
  REFTABLE_ALLOC_GROW_OR_NULL(w->index, w->index_len + 1, w->index_cap);
  if (!w->index)
    return REFTABLE_OUT_OF_MEMORY_ERROR;

  index_record.offset = w->next;
  reftable_buf_reset(&index_record.last_key);
  err = reftable_buf_add(&index_record.last_key, w->block_writer->last_key.buf,
             w->block_writer->last_key.len);
  if (err < 0)
    return err;
  w->index[w->index_len] = index_record;
  w->index_len++;

  w->next += padding + raw_bytes;
  w->block_writer = NULL;

  return 0;
}

static int writer_flush_block(struct reftable_writer *w)
{
  if (!w->block_writer)
    return 0;
  if (w->block_writer->entries == 0)
    return 0;
  return writer_flush_nonempty_block(w);
}

const struct reftable_stats *reftable_writer_stats(struct reftable_writer *w)
{
  return &w->stats;
}

Coverage Report

Created: 2025-12-31 07:01