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support for compressed index keys and trailing leaves

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brianb
2004-02-11 22:05:13 +00:00
parent 06115eaf59
commit a62f26df50
5 changed files with 139 additions and 44 deletions
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25
src/libmdb/write.c
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@@ -134,12 +134,8 @@ int eod, len; /* end of data */
/* find the end of data pointer */
eod = mdb_pg_get_int16(mdb, row_end - 3 - var_cols*2 - bitmask_sz);
if (IS_JET4(mdb)) {
col_start = 2;
} else {
/* data starts at 1 */
col_start = 1;
}
col_start = 2;
/* actual cols on this row */
fixed_cols_found = 0;
var_cols_found = 0;
@@ -199,7 +195,11 @@ int num_of_jumps = 0, jumps_used = 0;
int eod, len; /* end of data */
num_cols = mdb->pg_buf[row_start];
if (num_cols != table->num_cols) {
fprintf(stderr,"WARNING: number of table columns does not match number of row columns, strange results may occur\n");
}
/* how many fixed cols? */
for (i = 0; i < table->num_cols; i++) {
col = g_ptr_array_index (table->columns, i);
if (mdb_is_fixed_col(col)) {
@@ -209,6 +209,7 @@ int eod, len; /* end of data */
fields[totcols++].is_fixed = 1;
}
}
/* how many var cols? */
for (i = 0; i < table->num_cols; i++) {
col = g_ptr_array_index (table->columns, i);
if (!mdb_is_fixed_col(col)) {
@@ -251,7 +252,6 @@ int eod, len; /* end of data */
}
}
//fprintf(stderr, "col_start: %d\n", col_start);
/* if fixed columns add up to more than 256, we need a jump */
int col_ptr = row_end - bitmask_sz - num_of_jumps - 1;
if (col_start >= 256) {
@@ -261,6 +261,9 @@ int eod, len; /* end of data */
}
col_start = row_start;
/* compute the number of jumps (row size - overhead) / 256
* but you have to include the jump table itself, thus
* the loop. */
while (col_start+256 < row_end-bitmask_sz-1-var_cols-num_of_jumps){
col_start += 256;
num_of_jumps++;
@@ -268,12 +271,18 @@ int eod, len; /* end of data */
if (mdb->pg_buf[col_ptr]==0xFF) {
col_ptr--;
}
/* col_start is now the offset to the first variable length field */
col_start = mdb->pg_buf[col_ptr];
for (j=0;j<table->num_cols;j++) {
col = g_ptr_array_index(table->columns,j);
/* if it's a var_col and we aren't looking at a column
* added after this row was created */
if (!mdb_is_fixed_col(col) && ++var_cols_found <= var_cols) {
/* if the position of this var_col matches the number
* in the current jump table entry, then increment
* the jump_used and adjust the col/row_start */
if (var_cols_found == mdb->pg_buf[row_end-bitmask_sz-jumps_used-1] &&
jumps_used < num_of_jumps) {
row_start += 256;
@@ -281,6 +290,8 @@ int eod, len; /* end of data */
jumps_used++;
}
/* if we have the last var_col, use the eod offset to
* figure out where the end is */
if (var_cols_found==var_cols) {
len=eod - col_start;
//printf("len = %d eod %d col_start %d\n",len, eod, col_start);