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A fix for bug #669739 that became a mdb_crack_row4 rewrite. Thanks to Luciano Miguel Wolf and Alexandre Horst for the bug analysis and the initial patch.

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This commit is contained in:
whydoubt
2004-08-05 03:33:41 +00:00
parent 8cd1797f3c
commit f2125dd3bc
5 changed files with 61 additions and 99 deletions
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1
src/libmdb/table.c
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@@ -79,6 +79,7 @@ MdbTableDef *mdb_read_table(MdbCatalogEntry *entry)
len = mdb_pg_get_int16(mdb,8);
table->num_rows = mdb_pg_get_int32(mdb, fmt->tab_num_rows_offset);
table->num_var_cols = mdb_pg_get_int16(mdb, fmt->tab_num_cols_offset-2);
table->num_cols = mdb_pg_get_int16(mdb, fmt->tab_num_cols_offset);
table->num_idxs = mdb_pg_get_int32(mdb, fmt->tab_num_idxs_offset);
table->num_real_idxs = mdb_pg_get_int32(mdb, fmt->tab_num_ridxs_offset);

140
src/libmdb/write.c
View File

@@ -93,119 +93,69 @@ mdb_crack_row4(MdbTableDef *table, int row_start, int row_end, MdbField *fields)
MdbCatalogEntry *entry = table->entry;
MdbHandle *mdb = entry->mdb;
MdbColumn *col;
unsigned char *pg_buf = mdb->pg_buf;
unsigned int i;
int var_cols = 0, row_var_cols, fixed_cols = 0, row_fixed_cols, num_cols;
int var_cols_found, fixed_cols_found, var_entry_pos;
int col_start, next_col;
unsigned int row_var_cols=0, row_fixed_cols, row_cols;
unsigned int fixed_cols_found;
unsigned int col_start;
unsigned char *nullmask;
int bitmask_sz;
int byte_num, bit_num;
int eod, len; /* end of data */
int real_offset = 0;
int row_pos;
unsigned int bitmask_sz;
unsigned int byte_num, bit_num;
unsigned int *var_col_offsets = NULL;
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+1);
}
num_cols = mdb_pg_get_int16(mdb, row_start);
row_cols = mdb_pg_get_int16(mdb, row_start);
/* compute nulls first to help with fixed colnum's */
bitmask_sz = (num_cols - 1) / 8 + 1;
nullmask = &mdb->pg_buf[row_end - bitmask_sz + 1];
bitmask_sz = (row_cols + 7) / 8;
nullmask = &pg_buf[row_end - bitmask_sz + 1];
for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index (table->columns, i);
row_pos = col->col_num;
byte_num = row_pos / 8;
bit_num = row_pos % 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("row_pos %d col %d is %s\n", row_pos, i, fields[i].is_null ? "null" : "not null");
}
/* fields are ordered fixed then variable */
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;
if (table->num_var_cols > 0) {
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));
for (i=0; i<row_var_cols+1; i++) {
var_col_offsets[i] = mdb_pg_get_int16(mdb,
row_end - bitmask_sz - 3 - (i*2));
}
}
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;
}
}
row_var_cols = mdb_pg_get_int16(mdb, row_end - bitmask_sz - 1);
/* find the end of data pointer */
eod = mdb_pg_get_int16(mdb, row_end - 3 - var_cols*2 - bitmask_sz);
/* actual cols on this row */
fixed_cols_found = 0;
var_cols_found = 0;
row_fixed_cols = num_cols - row_var_cols;
row_fixed_cols = row_cols - row_var_cols;
for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index(table->columns,i);
if (mdb_is_fixed_col(col)) {
if (fixed_cols_found <= row_fixed_cols) {
real_offset += col->col_size;
fields[i].start = row_start + col->fixed_offset + 2;
fields[i].value = &mdb->pg_buf[row_start + col->fixed_offset + 2];
} else {
fields[i].start = 0;
fields[i].value = NULL;
fields[i].siz = 0;
fields[i].is_null = 1;
}
fields[i].colnum = i;
fields[i].is_fixed = (mdb_is_fixed_col(col)) ? 1 : 0;
byte_num = col->col_num / 8;
bit_num = col->col_num % 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;
if ((fields[i].is_fixed)
&& (fixed_cols_found <= row_fixed_cols)) {
col_start = col->fixed_offset + 2;
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++;
} else if ((!fields[i].is_fixed)
&& (col->var_col_num < row_var_cols)) {
col_start = var_col_offsets[col->var_col_num];
fields[i].start = row_start + col_start;
fields[i].value = &pg_buf[row_start + col_start];
fields[i].siz = var_col_offsets[(col->var_col_num)+1] -
col_start;
} 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 = mdb_pg_get_int16(mdb, row_end - 3 - bitmask_sz);
for (i=0;i<table->num_cols;i++) {
col = g_ptr_array_index(table->columns,i);
if (!mdb_is_fixed_col(col)) {
var_cols_found++;
if (var_cols_found <= row_var_cols) {
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 {
/* position of the var table
* entry for this column */
var_entry_pos =
row_end -
bitmask_sz -
var_cols_found * 2 - 2 - 1;
next_col = mdb_pg_get_int16(mdb, var_entry_pos);
len = next_col - col_start;
} /* if found==var_cols */
//printf("len = %d eod %d col_start %d\n",len, eod, col_start);
//printf("is_null %d\n",fields[i].is_null);
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;
return row_cols;
}
static int
mdb_crack_row3(MdbTableDef *table, int row_start, int row_end, MdbField *fields)