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C: now completely unmapping files before truncating them to a smaller

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size (#68)
This commit is contained in:
MercierC
2021-03-11 15:12:40 +13:00
parent 41fbae7b6c
commit 7f0f63cf26
4 changed files with 156 additions and 34 deletions
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35
src/obidmscolumn.c
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@ -1769,6 +1769,7 @@ int obi_truncate_column(OBIDMS_column_p column) // TODO is it necessary to unmap
{
size_t file_size;
size_t data_size;
size_t header_size;
index_t new_line_count;
double multiple;
int column_file_descriptor;
@ -1791,6 +1792,8 @@ int obi_truncate_column(OBIDMS_column_p column) // TODO is it necessary to unmap
data_size = obi_array_sizeof((column->header)->stored_data_type, new_line_count, (column->header)->nb_elements_per_line);
header_size = (column->header)->header_size;
// Check that it is actually greater than the current data size, otherwise no need to truncate
if ((column->header)->data_size == data_size)
return 0;
@ -1855,7 +1858,7 @@ int obi_truncate_column(OBIDMS_column_p column) // TODO is it necessary to unmap
return -1;
}
// Unmap the data before truncating the file
// Unmap the entire file before truncating it (WSL requirement)
if (munmap(column->data, (column->header)->data_size) < 0)
{
obi_set_errno(OBICOL_UNKNOWN_ERROR);
@ -1863,9 +1866,16 @@ int obi_truncate_column(OBIDMS_column_p column) // TODO is it necessary to unmap
close(column_file_descriptor);
return -1;
}
if (munmap(column->header, header_size) < 0)
{
obi_set_errno(OBICOL_UNKNOWN_ERROR);
obidebug(1, "\nError munmapping the header of a column before truncating");
close(column_file_descriptor);
return -1;
}
// Truncate the column file
file_size = (column->header)->header_size + data_size;
file_size = header_size + data_size;
if (ftruncate(column_file_descriptor, file_size) < 0)
{
obi_set_errno(OBICOL_UNKNOWN_ERROR);
@ -1874,13 +1884,30 @@ int obi_truncate_column(OBIDMS_column_p column) // TODO is it necessary to unmap
return -1;
}
// Remap the data
// Remap the header and the data
column->header = mmap(NULL,
header_size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
column_file_descriptor,
0
);
if (column->header == MAP_FAILED)
{
obi_set_errno(OBICOL_UNKNOWN_ERROR);
obidebug(1, "\nError re-mmapping the header of a column after truncating");
close(column_file_descriptor);
return -1;
}
column->data = mmap(NULL,
data_size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
column_file_descriptor,
(column->header)->header_size
header_size
);
if (column->data == MAP_FAILED)