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mdb_crack_row3 rewrite

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whydoubt
2004-08-27 03:45:53 +00:00
parent 13e824dbea
commit 139752bf3a
2 changed files with 69 additions and 143 deletions
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ChangeLog
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@@ -2,6 +2,7 @@ Thu Aug 26 21:06:35 CDT 2004 Jeff Smith <whydoubt@yahoo.com>
* src/libmdb/write.c: Documentation fix * src/libmdb/write.c: Documentation fix
* src/sql/lexer.l: Add SQL quote escaping * src/sql/lexer.l: Add SQL quote escaping
* src/libmdb/worktable.c: Fix bug in creating temp tables * src/libmdb/worktable.c: Fix bug in creating temp tables
* src/libmdb/write.c: mdb_crack_row3 rewrite
Tue Aug 24 21:04:17 CDT 2004 Jeff Smith <whydoubt@yahoo.com> Tue Aug 24 21:04:17 CDT 2004 Jeff Smith <whydoubt@yahoo.com>
* include/mdbsql.h: * include/mdbsql.h:

211
src/libmdb/write.c
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@@ -112,6 +112,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
bitmask_sz = (row_cols + 7) / 8; bitmask_sz = (row_cols + 7) / 8;
nullmask = &pg_buf[row_end - bitmask_sz + 1]; nullmask = &pg_buf[row_end - bitmask_sz + 1];
/* read table of variable column locations */
if (table->num_var_cols > 0) { if (table->num_var_cols > 0) {
row_var_cols = mdb_pg_get_int16(mdb, row_end - bitmask_sz - 1); row_var_cols = mdb_pg_get_int16(mdb, row_end - bitmask_sz - 1);
var_col_offsets = (int *)g_malloc((row_var_cols+1)*sizeof(int)); var_col_offsets = (int *)g_malloc((row_var_cols+1)*sizeof(int));
@@ -123,6 +124,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
fixed_cols_found = 0; fixed_cols_found = 0;
row_fixed_cols = row_cols - row_var_cols; row_fixed_cols = row_cols - row_var_cols;
/* read information into fields[] */
for (i=0;i<table->num_cols;i++) { for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index(table->columns,i); col = g_ptr_array_index(table->columns,i);
fields[i].colnum = i; fields[i].colnum = i;
@@ -133,7 +135,7 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
fields[i].is_null = nullmask[byte_num] & (1 << bit_num) ? 0 : 1; fields[i].is_null = nullmask[byte_num] & (1 << bit_num) ? 0 : 1;
if ((fields[i].is_fixed) if ((fields[i].is_fixed)
&& (fixed_cols_found <= row_fixed_cols)) { && (fixed_cols_found < row_fixed_cols)) {
col_start = col->fixed_offset + 2; col_start = col->fixed_offset + 2;
fields[i].start = row_start + col_start; fields[i].start = row_start + col_start;
fields[i].value = &pg_buf[row_start + col_start]; fields[i].value = &pg_buf[row_start + col_start];
@@ -163,169 +165,92 @@ mdb_crack_row3(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
MdbCatalogEntry *entry = table->entry; MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb; MdbHandle *mdb = entry->mdb;
MdbColumn *col; MdbColumn *col;
unsigned char *pg_buf = mdb->pg_buf;
unsigned int i; unsigned int i;
int var_cols = 0, fixed_cols = 0, num_cols; unsigned int row_var_cols = 0, row_fixed_cols, row_cols;
int row_var_cols = 0, row_fixed_cols = 0; unsigned int fixed_cols_found, var_cols_found;
int var_cols_found, fixed_cols_found, var_entry_pos; unsigned int col_start;
int col_start;
unsigned char *nullmask; unsigned char *nullmask;
int bitmask_sz; unsigned int bitmask_sz;
int byte_num, bit_num; unsigned int byte_num, bit_num;
int num_of_jumps = 0, jumps_used = 0; unsigned int *var_col_offsets = NULL;
int eod, len; /* end of data */ unsigned int num_jumps = 0, jumps_used = 0;
int row_pos, col_ptr; unsigned int col_ptr, row_len;
if (mdb_get_option(MDB_DEBUG_ROW)) { if (mdb_get_option(MDB_DEBUG_ROW)) {
buffer_dump(mdb->pg_buf, row_start, row_end+1); buffer_dump(pg_buf, row_start, row_end);
} }
num_cols = mdb->pg_buf[row_start]; row_cols = pg_buf[row_start];
//if (num_cols != table->num_cols) { bitmask_sz = (row_cols + 7) / 8;
//fprintf(stderr,"WARNING: number of table columns does not match number of row columns, strange results may occur\n"); nullmask = &pg_buf[row_end - bitmask_sz + 1];
//}
/* compute nulls first to help with fixed colnum's */ /* read table of variable column locations */
bitmask_sz = (num_cols - 1) / 8 + 1; if (table->num_var_cols > 0) {
nullmask = &mdb->pg_buf[row_end - bitmask_sz + 1]; row_var_cols = pg_buf[row_end - bitmask_sz];
row_len = row_end - row_start + 1;
num_jumps = 0;
while (num_jumps < (row_len-bitmask_sz-row_var_cols-num_jumps-2)/256) {
num_jumps ++;
}
col_ptr = row_end - bitmask_sz - num_jumps - 1;
for (i=0;i<table->num_cols;i++) { var_col_offsets = (int *)g_malloc((row_var_cols+1)*sizeof(int));
col = g_ptr_array_index (table->columns, i); jumps_used = 0;
row_pos = col->col_num; for (i=0; i<row_var_cols+1; i++) {
byte_num = row_pos / 8; if ((jumps_used < num_jumps)
bit_num = row_pos % 8; && (i == pg_buf[row_end-bitmask_sz-jumps_used-1])) {
/* logic on nulls is reverse, 1 is not null, 0 is null */ jumps_used++;
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"); var_col_offsets[i] = pg_buf[col_ptr-i]+(jumps_used*256);
}
/* 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)) {
fixed_cols++;
fields[i].colnum = i;
fields[i].siz = col->col_size;
fields[i].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)) {
var_cols++;
fields[i].colnum = i;
fields[i].is_fixed = 0;
}
}
/* find the end of data pointer */
eod = mdb->pg_buf[row_end-1-var_cols-bitmask_sz];
/* data starts at 1 */
col_start = 1;
/* actual cols on this row */
fixed_cols_found = 0; fixed_cols_found = 0;
var_cols_found = 0; var_cols_found = 0;
row_fixed_cols = row_cols - row_var_cols;
/* if fixed columns add up to more than 256, we need a jump */
if (col_start >= 256) {
num_of_jumps++;
jumps_used++;
row_start = row_start + col_start - (col_start % 256);
}
/* compute the number of jumps (row size - overhead) / 256
* but you have to include the jump table itself, thus
* the loop. */
col_start = row_start;
while (col_start+256 < row_end-bitmask_sz-1-var_cols-num_of_jumps){
col_start += 256;
num_of_jumps++;
}
col_ptr = row_end - bitmask_sz - num_of_jumps - 1;
if (mdb->pg_buf[col_ptr]==0xFF) {
col_ptr--;
}
row_var_cols = mdb->pg_buf[row_end - bitmask_sz - num_of_jumps];
row_fixed_cols = num_cols - row_var_cols;
if (mdb_get_option(MDB_DEBUG_ROW)) { if (mdb_get_option(MDB_DEBUG_ROW)) {
fprintf(stdout,"bitmask_sz %d num_of_jumps %d\n",bitmask_sz, num_of_jumps); fprintf(stdout,"bitmask_sz %d num_jumps %d\n",bitmask_sz, num_jumps);
fprintf(stdout,"var_cols %d row_var_cols %d\n",var_cols, row_var_cols); fprintf(stdout,"row_var_cols %d\n", row_var_cols);
fprintf(stdout,"fixed_cols %d row_fixed_cols %d\n",fixed_cols, row_fixed_cols); fprintf(stdout,"row_fixed_cols %d\n", row_fixed_cols);
} }
/* loop through fixed columns and add values to fields[] */
/* read information into fields[] */
for (i=0;i<table->num_cols;i++) { for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index(table->columns,i); col = g_ptr_array_index (table->columns, i);
if (mdb_is_fixed_col(col)) { fields[i].colnum = i;
if (fixed_cols_found <= row_fixed_cols) { fields[i].is_fixed = (mdb_is_fixed_col(col)) ? 1 : 0;
fields[i].start = row_start + col->fixed_offset + 1; byte_num = col->col_num / 8;
fields[i].value = &mdb->pg_buf[row_start + col->fixed_offset + 1]; bit_num = col->col_num % 8;
if (col->col_type != MDB_BOOL) /* logic on nulls is reverse, 1 is not null, 0 is null */
col_start += col->col_size; fields[i].is_null = nullmask[byte_num] & (1 << bit_num) ? 0 : 1;
} else {
fields[i].start = 0; if ((fields[i].is_fixed)
fields[i].value = NULL; && (fixed_cols_found < row_fixed_cols)) {
fields[i].siz = 0; col_start = col->fixed_offset + 1;
fields[i].is_null = 1; fields[i].start = row_start + col_start;
} fields[i].value = &pg_buf[row_start + col_start];
fields[i].siz = col->col_size;
fixed_cols_found++; fixed_cols_found++;
} else if ((!fields[i].is_fixed)
&& (var_cols_found < row_var_cols)) {
col_start = var_col_offsets[var_cols_found];
fields[i].start = row_start + col_start;
fields[i].value = &pg_buf[row_start + col_start];
fields[i].siz = var_col_offsets[var_cols_found+1] -
col_start;
var_cols_found++;
} else {
fields[i].start = 0;
fields[i].value = NULL;
fields[i].siz = 0;
fields[i].is_null = 1;
} }
} }
g_free(var_col_offsets);
/* col_start is now the offset to the first variable length field */ return row_cols;
col_start = mdb->pg_buf[col_ptr];
//fprintf(stdout,"col_ptr %d col_start %d\n",col_ptr, col_start);
for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index(table->columns,i);
/* 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++;
if (var_cols_found <= row_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;
col_start -= 256;
jumps_used++;
}
/* if we have the last var_col, use the eod offset to
* figure out where the end is */
if (var_cols_found==row_var_cols) {
len=eod - col_start;
//printf("len = %d eod %d col_start %d\n",len, eod, col_start);
} else {
var_entry_pos =
row_end -
bitmask_sz -
var_cols_found - 1;
len=mdb->pg_buf[var_entry_pos] - col_start;
} /* if found==var_cols */
while (len<0) len+=256;
fields[i].start = row_start + col_start;
fields[i].value = &mdb->pg_buf[row_start +col_start];
fields[i].siz = len;
col_start += len;
} else {
fields[i].start = 0;
fields[i].value = NULL;
fields[i].siz = 0;
fields[i].is_null = 1;
}
} /* if !fixed */
} /* for */
return num_cols;
} }
/** /**
* mdb_crack_row: * mdb_crack_row: