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Enable multi-page temp tables

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This commit is contained in:
whydoubt
2004-09-09 03:44:35 +00:00
parent 8fa51d0431
commit 56995ff968
9 changed files with 87 additions and 85 deletions
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69
src/libmdb/write.c
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@@ -449,14 +449,14 @@ mdb_pack_row(MdbTableDef *table, unsigned char *row_buffer, int unsigned num_fie
int
mdb_pg_get_freespace(MdbHandle *mdb)
{
MdbFormatConstants *fmt = mdb->fmt;
int rows, free_start, free_end;
int rows, free_start, free_end;
int row_count_offset = mdb->fmt->row_count_offset;
rows = mdb_pg_get_int16(mdb, fmt->row_count_offset);
free_start = fmt->row_count_offset + 2 + (rows * 2);
free_end = mdb_pg_get_int16(mdb, (fmt->row_count_offset + rows * 2)) -1;
rows = mdb_pg_get_int16(mdb, row_count_offset);
free_start = row_count_offset + 2 + (rows * 2);
free_end = mdb_pg_get_int16(mdb, row_count_offset + (rows * 2));
mdb_debug(MDB_DEBUG_WRITE,"free space left on page = %d", free_end - free_start);
return (free_end - free_start + 1);
return (free_end - free_start);
}
unsigned char *
mdb_new_leaf_pg(MdbCatalogEntry *entry)
@@ -475,13 +475,14 @@ mdb_new_leaf_pg(MdbCatalogEntry *entry)
unsigned char *
mdb_new_data_pg(MdbCatalogEntry *entry)
{
MdbHandle *mdb = entry->mdb;
MdbFormatConstants *fmt = entry->mdb->fmt;
unsigned char *new_pg;
new_pg = (unsigned char *) g_malloc0(mdb->fmt->pg_size);
new_pg = (unsigned char *) g_malloc0(fmt->pg_size);
new_pg[0]=0x01;
new_pg[1]=0x01;
_mdb_put_int16(new_pg, 2, fmt->pg_size - fmt->row_count_offset - 2);
_mdb_put_int32(new_pg, 4, entry->table_pg);
return new_pg;
@@ -613,19 +614,37 @@ mdb_add_row_to_pg(MdbTableDef *table, unsigned char *row_buffer, int new_row_siz
MdbHandle *mdb = entry->mdb;
MdbFormatConstants *fmt = mdb->fmt;
new_pg = mdb_new_data_pg(entry);
if (table->is_temp_table) {
GPtrArray *pages = table->temp_table_pages;
if (pages->len == 0) {
new_pg = mdb_new_data_pg(entry);
g_ptr_array_add(pages, new_pg);
} else {
new_pg = g_ptr_array_index(pages, pages->len - 1);
if (mdb_get_int16(new_pg, 2) < new_row_size + 2) {
new_pg = mdb_new_data_pg(entry);
g_ptr_array_add(pages, new_pg);
}
}
num_rows = mdb_pg_get_int16(mdb, fmt->row_count_offset);
pos = mdb->fmt->pg_size;
num_rows = mdb_get_int16(new_pg, fmt->row_count_offset);
pos = (num_rows == 0) ? fmt->pg_size :
mdb_get_int16(new_pg, fmt->row_count_offset + (num_rows*2));
} else { /* is not a temp table */
new_pg = mdb_new_data_pg(entry);
/* copy existing rows */
for (i=0;i<num_rows;i++) {
row_start = mdb_pg_get_int16(mdb, (fmt->row_count_offset + 2) + (i*2));
row_end = mdb_find_end_of_row(mdb, i);
row_size = row_end - row_start + 1;
pos -= row_size;
memcpy(&new_pg[pos], &mdb->pg_buf[row_start], row_size);
_mdb_put_int16(new_pg, (fmt->row_count_offset + 2) + (i*2), pos);
num_rows = mdb_pg_get_int16(mdb, fmt->row_count_offset);
pos = fmt->pg_size;
/* copy existing rows */
for (i=0;i<num_rows;i++) {
row_start = mdb_pg_get_int16(mdb, (fmt->row_count_offset + 2) + (i*2));
row_end = mdb_find_end_of_row(mdb, i);
row_size = row_end - row_start + 1;
pos -= row_size;
memcpy(&new_pg[pos], &mdb->pg_buf[row_start], row_size);
_mdb_put_int16(new_pg, (fmt->row_count_offset + 2) + (i*2), pos);
}
}
/* add our new row */
@@ -638,12 +657,14 @@ mdb_add_row_to_pg(MdbTableDef *table, unsigned char *row_buffer, int new_row_siz
num_rows++;
_mdb_put_int16(new_pg, fmt->row_count_offset, num_rows);
/* copy new page over old */
memcpy(mdb->pg_buf, new_pg, fmt->pg_size);
g_free(new_pg);
/* update the freespace */
_mdb_put_int16(mdb->pg_buf, 2, mdb_pg_get_freespace(mdb));
_mdb_put_int16(new_pg,2,pos - fmt->row_count_offset - 2 - (num_rows*2));
/* copy new page over old */
if (!table->is_temp_table) {
memcpy(mdb->pg_buf, new_pg, fmt->pg_size);
g_free(new_pg);
}
return num_rows;
}