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add IS NULL/IS NOT NULL support, patches

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brianb
2004-02-06 23:55:18 +00:00
parent af7b6953ad
commit 5f02ba4fd2
10 changed files with 211 additions and 145 deletions
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32
src/libmdb/write.c
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@@ -195,6 +195,7 @@ int col_start, next_col;
unsigned char *nullmask;
int bitmask_sz;
int byte_num, bit_num;
int num_of_jumps = 0, jumps_used = 0;
int eod, len; /* end of data */
num_cols = mdb->pg_buf[row_start];
@@ -225,6 +226,7 @@ int eod, len; /* end of data */
bit_num = i % 8;
/* logic on nulls is reverse, 1 is not null, 0 is null */
fields[i].is_null = nullmask[byte_num] & 1 << bit_num ? 0 : 1;
//printf("col %d is %s\n", i, fields[i].is_null ? "null" : "not null");
}
/* find the end of data pointer */
@@ -248,9 +250,37 @@ int eod, len; /* end of data */
col_start += col->col_size;
}
}
//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) {
num_of_jumps++;
jumps_used++;
row_start = row_start + col_start - (col_start % 256);
}
col_start = row_start;
while (col_start+256 < row_end-bitmask_sz-1-var_cols-num_of_jumps){
col_start += 256;
num_of_jumps++;
}
if (mdb->pg_buf[col_ptr]==0xFF) {
col_ptr--;
}
col_start = mdb->pg_buf[col_ptr];
for (j=0;j<table->num_cols;j++) {
col = g_ptr_array_index(table->columns,j);
if (!mdb_is_fixed_col(col) && ++var_cols_found <= var_cols) {
if (var_cols_found == mdb->pg_buf[row_end-bitmask_sz-jumps_used-1] &&
jumps_used < num_of_jumps) {
row_start += 256;
col_start -= 256;
jumps_used++;
}
if (var_cols_found==var_cols) {
len=eod - col_start;
//printf("len = %d eod %d col_start %d\n",len, eod, col_start);
@@ -324,7 +354,7 @@ int i;
byte = 0;
bit = 0;
for (i=0;i<num_fields;i++) {
/* column is null is bit is clear (0) */
/* column is null if bit is clear (0) */
if (!fields[i].is_null) {
byte |= 1 << bit;
//printf("%d %d %d %d\n", i, bit, 1 << bit, byte);