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mdb_crack_row3 rewrite
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whydoubt
@@ -2,6 +2,7 @@ Thu Aug 26 21:06:35 CDT 2004 Jeff Smith <whydoubt@yahoo.com>
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* src/libmdb/write.c: Documentation fix
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* src/sql/lexer.l: Add SQL quote escaping
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* src/libmdb/worktable.c: Fix bug in creating temp tables
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* src/libmdb/write.c: mdb_crack_row3 rewrite
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Tue Aug 24 21:04:17 CDT 2004 Jeff Smith <whydoubt@yahoo.com>
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* include/mdbsql.h:
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@@ -112,6 +112,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
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bitmask_sz = (row_cols + 7) / 8;
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nullmask = &pg_buf[row_end - bitmask_sz + 1];
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/* read table of variable column locations */
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if (table->num_var_cols > 0) {
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row_var_cols = mdb_pg_get_int16(mdb, row_end - bitmask_sz - 1);
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var_col_offsets = (int *)g_malloc((row_var_cols+1)*sizeof(int));
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@@ -123,6 +124,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
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fixed_cols_found = 0;
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row_fixed_cols = row_cols - row_var_cols;
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/* read information into fields[] */
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for (i=0;i<table->num_cols;i++) {
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col = g_ptr_array_index(table->columns,i);
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fields[i].colnum = i;
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@@ -133,7 +135,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
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fields[i].is_null = nullmask[byte_num] & (1 << bit_num) ? 0 : 1;
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if ((fields[i].is_fixed)
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&& (fixed_cols_found <= row_fixed_cols)) {
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&& (fixed_cols_found < row_fixed_cols)) {
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col_start = col->fixed_offset + 2;
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fields[i].start = row_start + col_start;
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fields[i].value = &pg_buf[row_start + col_start];
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@@ -163,169 +165,92 @@ mdb_crack_row3(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
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MdbCatalogEntry *entry = table->entry;
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MdbHandle *mdb = entry->mdb;
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MdbColumn *col;
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unsigned char *pg_buf = mdb->pg_buf;
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unsigned int i;
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int var_cols = 0, fixed_cols = 0, num_cols;
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int row_var_cols = 0, row_fixed_cols = 0;
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int var_cols_found, fixed_cols_found, var_entry_pos;
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int col_start;
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unsigned int row_var_cols = 0, row_fixed_cols, row_cols;
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unsigned int fixed_cols_found, var_cols_found;
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unsigned int col_start;
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unsigned char *nullmask;
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int bitmask_sz;
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int byte_num, bit_num;
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int num_of_jumps = 0, jumps_used = 0;
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int eod, len; /* end of data */
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int row_pos, col_ptr;
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unsigned int bitmask_sz;
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unsigned int byte_num, bit_num;
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unsigned int *var_col_offsets = NULL;
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unsigned int num_jumps = 0, jumps_used = 0;
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unsigned int col_ptr, row_len;
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if (mdb_get_option(MDB_DEBUG_ROW)) {
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buffer_dump(mdb->pg_buf, row_start, row_end+1);
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buffer_dump(pg_buf, row_start, row_end);
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}
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num_cols = mdb->pg_buf[row_start];
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row_cols = pg_buf[row_start];
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//if (num_cols != table->num_cols) {
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//fprintf(stderr,"WARNING: number of table columns does not match number of row columns, strange results may occur\n");
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//}
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bitmask_sz = (row_cols + 7) / 8;
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nullmask = &pg_buf[row_end - bitmask_sz + 1];
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/* compute nulls first to help with fixed colnum's */
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bitmask_sz = (num_cols - 1) / 8 + 1;
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nullmask = &mdb->pg_buf[row_end - bitmask_sz + 1];
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/* read table of variable column locations */
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if (table->num_var_cols > 0) {
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row_var_cols = pg_buf[row_end - bitmask_sz];
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row_len = row_end - row_start + 1;
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num_jumps = 0;
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while (num_jumps < (row_len-bitmask_sz-row_var_cols-num_jumps-2)/256) {
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num_jumps ++;
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}
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col_ptr = row_end - bitmask_sz - num_jumps - 1;
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for (i=0;i<table->num_cols;i++) {
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col = g_ptr_array_index (table->columns, i);
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row_pos = col->col_num;
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byte_num = row_pos / 8;
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bit_num = row_pos % 8;
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/* logic on nulls is reverse, 1 is not null, 0 is null */
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fields[i].is_null = nullmask[byte_num] & 1 << bit_num ? 0 : 1;
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//printf("col %d is %s\n", i, fields[i].is_null ? "null" : "not null");
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}
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/* how many fixed cols? */
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for (i = 0; i < table->num_cols; i++) {
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col = g_ptr_array_index (table->columns, i);
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if (mdb_is_fixed_col(col)) {
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fixed_cols++;
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fields[i].colnum = i;
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fields[i].siz = col->col_size;
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fields[i].is_fixed = 1;
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var_col_offsets = (int *)g_malloc((row_var_cols+1)*sizeof(int));
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jumps_used = 0;
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for (i=0; i<row_var_cols+1; i++) {
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if ((jumps_used < num_jumps)
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&& (i == pg_buf[row_end-bitmask_sz-jumps_used-1])) {
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jumps_used++;
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}
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var_col_offsets[i] = pg_buf[col_ptr-i]+(jumps_used*256);
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}
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}
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/* how many var cols? */
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for (i = 0; i < table->num_cols; i++) {
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col = g_ptr_array_index (table->columns, i);
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if (!mdb_is_fixed_col(col)) {
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var_cols++;
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fields[i].colnum = i;
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fields[i].is_fixed = 0;
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}
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}
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/* find the end of data pointer */
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eod = mdb->pg_buf[row_end-1-var_cols-bitmask_sz];
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/* data starts at 1 */
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col_start = 1;
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/* actual cols on this row */
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fixed_cols_found = 0;
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var_cols_found = 0;
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/* if fixed columns add up to more than 256, we need a jump */
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if (col_start >= 256) {
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num_of_jumps++;
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jumps_used++;
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row_start = row_start + col_start - (col_start % 256);
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}
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/* compute the number of jumps (row size - overhead) / 256
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* but you have to include the jump table itself, thus
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* the loop. */
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col_start = row_start;
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while (col_start+256 < row_end-bitmask_sz-1-var_cols-num_of_jumps){
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col_start += 256;
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num_of_jumps++;
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}
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col_ptr = row_end - bitmask_sz - num_of_jumps - 1;
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if (mdb->pg_buf[col_ptr]==0xFF) {
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col_ptr--;
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}
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row_var_cols = mdb->pg_buf[row_end - bitmask_sz - num_of_jumps];
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row_fixed_cols = num_cols - row_var_cols;
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row_fixed_cols = row_cols - row_var_cols;
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if (mdb_get_option(MDB_DEBUG_ROW)) {
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fprintf(stdout,"bitmask_sz %d num_of_jumps %d\n",bitmask_sz, num_of_jumps);
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fprintf(stdout,"var_cols %d row_var_cols %d\n",var_cols, row_var_cols);
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fprintf(stdout,"fixed_cols %d row_fixed_cols %d\n",fixed_cols, row_fixed_cols);
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fprintf(stdout,"bitmask_sz %d num_jumps %d\n",bitmask_sz, num_jumps);
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fprintf(stdout,"row_var_cols %d\n", row_var_cols);
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fprintf(stdout,"row_fixed_cols %d\n", row_fixed_cols);
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}
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/* loop through fixed columns and add values to fields[] */
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/* read information into fields[] */
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for (i=0;i<table->num_cols;i++) {
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col = g_ptr_array_index(table->columns,i);
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if (mdb_is_fixed_col(col)) {
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if (fixed_cols_found <= row_fixed_cols) {
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fields[i].start = row_start + col->fixed_offset + 1;
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fields[i].value = &mdb->pg_buf[row_start + col->fixed_offset + 1];
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if (col->col_type != MDB_BOOL)
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col_start += col->col_size;
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} else {
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fields[i].start = 0;
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fields[i].value = NULL;
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fields[i].siz = 0;
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fields[i].is_null = 1;
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}
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col = g_ptr_array_index (table->columns, i);
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fields[i].colnum = i;
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fields[i].is_fixed = (mdb_is_fixed_col(col)) ? 1 : 0;
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byte_num = col->col_num / 8;
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bit_num = col->col_num % 8;
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/* logic on nulls is reverse, 1 is not null, 0 is null */
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fields[i].is_null = nullmask[byte_num] & (1 << bit_num) ? 0 : 1;
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if ((fields[i].is_fixed)
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&& (fixed_cols_found < row_fixed_cols)) {
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col_start = col->fixed_offset + 1;
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fields[i].start = row_start + col_start;
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fields[i].value = &pg_buf[row_start + col_start];
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fields[i].siz = col->col_size;
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fixed_cols_found++;
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} else if ((!fields[i].is_fixed)
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&& (var_cols_found < row_var_cols)) {
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col_start = var_col_offsets[var_cols_found];
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fields[i].start = row_start + col_start;
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fields[i].value = &pg_buf[row_start + col_start];
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fields[i].siz = var_col_offsets[var_cols_found+1] -
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col_start;
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var_cols_found++;
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} else {
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fields[i].start = 0;
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fields[i].value = NULL;
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fields[i].siz = 0;
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fields[i].is_null = 1;
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}
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}
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g_free(var_col_offsets);
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/* col_start is now the offset to the first variable length field */
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col_start = mdb->pg_buf[col_ptr];
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//fprintf(stdout,"col_ptr %d col_start %d\n",col_ptr, col_start);
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for (i=0;i<table->num_cols;i++) {
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col = g_ptr_array_index(table->columns,i);
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/* if it's a var_col and we aren't looking at a column
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* added after this row was created */
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if (!mdb_is_fixed_col(col)) {
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var_cols_found++;
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if (var_cols_found <= row_var_cols) {
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/* if the position of this var_col matches the number
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* in the current jump table entry, then increment
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* the jump_used and adjust the col/row_start */
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if (var_cols_found == mdb->pg_buf[row_end-bitmask_sz-jumps_used-1] &&
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jumps_used < num_of_jumps) {
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row_start += 256;
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col_start -= 256;
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jumps_used++;
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}
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/* if we have the last var_col, use the eod offset to
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* figure out where the end is */
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if (var_cols_found==row_var_cols) {
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len=eod - col_start;
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//printf("len = %d eod %d col_start %d\n",len, eod, col_start);
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} else {
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var_entry_pos =
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row_end -
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bitmask_sz -
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var_cols_found - 1;
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len=mdb->pg_buf[var_entry_pos] - col_start;
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} /* if found==var_cols */
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while (len<0) len+=256;
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fields[i].start = row_start + col_start;
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fields[i].value = &mdb->pg_buf[row_start +col_start];
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fields[i].siz = len;
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col_start += len;
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} else {
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fields[i].start = 0;
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fields[i].value = NULL;
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fields[i].siz = 0;
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fields[i].is_null = 1;
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}
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} /* if !fixed */
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} /* for */
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return num_cols;
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return row_cols;
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}
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/**
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* mdb_crack_row:
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