/*
* Copy all relation data files from datadir_source to datadir_target, which
* are marked in the given data page map.
*/
void
copy_executeFileMap(filemap_t *map)
{
file_entry_t *entry;
for (entry = map->first; entry != NULL; entry = entry->next)
{
execute_pagemap(&entry->pagemap, entry->path);
switch (entry->action)
{
case FILE_ACTION_NONE:
/* ok, do nothing.. */
break;
case FILE_ACTION_COPY:
copy_file_range(entry->path, 0, entry->newsize, true);
break;
case FILE_ACTION_REMOVE:
remove_target_file(entry->path);
break;
case FILE_ACTION_TRUNCATE:
truncate_target_file(entry->path, entry->newsize);
break;
case FILE_ACTION_COPY_TAIL:
copy_file_range(entry->path, entry->oldsize, entry->newsize, false);
break;
case FILE_ACTION_CREATEDIR:
create_target_dir(entry->path);
break;
}
}
if (dstfd != -1)
close_target_file();
}
static void
execute_pagemap(datapagemap_t *pagemap, const char *path)
{
datapagemap_iterator_t *iter;
BlockNumber blkno;
iter = datapagemap_iterate(pagemap);
while (datapagemap_next(iter, &blkno))
{
off_t offset = blkno * BLCKSZ;
copy_file_range(path, offset, offset + BLCKSZ);
}
}
static void
execute_pagemap(datapagemap_t *pagemap, const char *path)
{
datapagemap_iterator_t *iter;
BlockNumber blkno;
iter = datapagemap_iterate(pagemap);
while (datapagemap_next(iter, &blkno))
{
off_t offset = blkno * BLCKSZ;
copy_file_range(path, offset, offset + BLCKSZ, false);
/* Ok, this block has now been copied from new data dir to old */
}
}
/*
* Fetch all changed blocks from remote source data directory.
*/
void
libpq_executeFileMap(filemap_t *map)
{
file_entry_t *entry;
const char *sql;
PGresult *res;
/*
* First create a temporary table, and load it with the blocks that
* we need to fetch.
*/
sql = "create temporary table fetchchunks(path text, begin int4, len int4);";
res = PQexec(conn, sql);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "error creating temporary table: %s\n",
PQresultErrorMessage(res));
exit(1);
}
sql = "copy fetchchunks from stdin";
res = PQexec(conn, sql);
if (PQresultStatus(res) != PGRES_COPY_IN)
{
fprintf(stderr, "unexpected result while sending file list: %s\n",
PQresultErrorMessage(res));
exit(1);
}
for (entry = map->first; entry != NULL; entry = entry->next)
{
execute_pagemap(&entry->pagemap, entry->path);
switch (entry->action)
{
case FILE_ACTION_NONE:
/* ok, do nothing.. */
break;
case FILE_ACTION_COPY:
/* Truncate the old file out of the way, if any */
open_target_file(entry->path, true);
copy_file_range(entry->path, 0, entry->newsize);
break;
case FILE_ACTION_REMOVE:
remove_target_file(entry->path);
break;
case FILE_ACTION_TRUNCATE:
truncate_target_file(entry->path, entry->newsize);
break;
case FILE_ACTION_COPY_TAIL:
copy_file_range(entry->path, entry->oldsize, entry->newsize);
break;
case FILE_ACTION_CREATEDIR:
create_target_dir(entry->path);
break;
case FILE_ACTION_REMOVEDIR:
remove_target_dir(entry->path);
break;
}
}
if (PQputCopyEnd(conn, NULL) != 1)
{
fprintf(stderr, "error sending end-of-COPY: %s\n",
PQerrorMessage(conn));
exit(1);
}
while ((res = PQgetResult(conn)) != NULL)
{
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "unexpected result while sending file list: %s\n",
PQresultErrorMessage(res));
exit(1);
}
}
/* Ok, we've sent the file list. Now receive the files */
sql =
"-- fetch all the blocks listed in the temp table.\n"
"select path, begin, \n"
" pg_read_binary_file(path, begin, len) as chunk\n"
"from fetchchunks\n";
receiveFileChunks(sql);
}
