bool SeqScanPlan::SerializeTo(SerializeOutput &output) {
// A placeholder for the total size written at the end
int start = output.Position();
output.WriteInt(-1);
// Write the SeqScanPlan type
PlanNodeType plan_type = GetPlanNodeType();
output.WriteByte(static_cast<int8_t>(plan_type));
// Write database id and table id
if (!GetTable()) {
// The plan is not completed
return false;
}
oid_t database_id = GetTable()->GetDatabaseOid();
oid_t table_id = GetTable()->GetOid();
output.WriteInt(static_cast<int>(database_id));
output.WriteInt(static_cast<int>(table_id));
// If column has 0 item, just write the columnid_count with 0
int columnid_count = GetColumnIds().size();
output.WriteInt(columnid_count);
// If column has 0 item, nothing happens here
for (int it = 0; it < columnid_count; it++) {
oid_t col_id = GetColumnIds()[it];
output.WriteInt(static_cast<int>(col_id));
}
// Write predicate
if (GetPredicate() == nullptr) {
// Write the type
output.WriteByte(static_cast<int8_t>(EXPRESSION_TYPE_INVALID));
} else {
// Write the expression type
ExpressionType expr_type = GetPredicate()->GetExpressionType();
output.WriteByte(static_cast<int8_t>(expr_type));
}
// Write parent, but parent seems never be set or used right now
if (GetParent() == nullptr) {
// Write the type
output.WriteByte(static_cast<int8_t>(PLAN_NODE_TYPE_INVALID));
} else {
// Write the parent type
PlanNodeType parent_type = GetParent()->GetPlanNodeType();
output.WriteByte(static_cast<int8_t>(parent_type));
// Write parent
GetParent()->SerializeTo(output);
}
// Write the total length
int32_t sz = static_cast<int32_t>(output.Position() - start - sizeof(int));
PL_ASSERT(sz > 0);
output.WriteIntAt(start, sz);
return true;
}
bool Tile::SerializeHeaderTo(SerializeOutput &output) {
std::size_t start;
// Use the cache if possible
if (column_header != NULL) {
PL_ASSERT(column_header_size != INVALID_OID);
output.WriteBytes(column_header, column_header_size);
return true;
}
PL_ASSERT(column_header_size == INVALID_OID);
// Skip header position
start = output.Position();
output.WriteInt(-1);
// Status code
output.WriteByte(-128);
// Column counts as a short
output.WriteShort(static_cast<int16_t>(column_count));
// Write an array of column types as bytes
for (oid_t column_itr = 0; column_itr < column_count; ++column_itr) {
type::Type::TypeId type = schema.GetType(column_itr);
output.WriteByte(static_cast<int8_t>(type));
}
// Write the array of column names as strings
// NOTE: strings are ASCII only in metadata (UTF-8 in table storage)
for (oid_t column_itr = 0; column_itr < column_count; ++column_itr) {
// Column name: Write (offset, length) for column definition, and string to
// string table
const std::string &name = GetColumnName(column_itr);
// Column names can't be null, so length must be >= 0
int32_t length = static_cast<int32_t>(name.size());
PL_ASSERT(length >= 0);
// this is standard string serialization for voltdb
output.WriteInt(length);
output.WriteBytes(name.data(), length);
}
// Write the header size which is a non-inclusive int
size_t Position = output.Position();
column_header_size = static_cast<int32_t>(Position - start);
int32_t non_inclusive_header_size =
static_cast<int32_t>(column_header_size - sizeof(int32_t));
output.WriteIntAt(start, non_inclusive_header_size);
// Cache the column header
column_header = new char[column_header_size];
PL_MEMCPY(column_header, static_cast<const char *>(output.Data()) + start,
column_header_size);
return true;
}
void Tuple::SerializeTo(SerializeOutput &output) {
PL_ASSERT(tuple_schema_);
size_t start = output.ReserveBytes(4);
const int column_count = tuple_schema_->GetColumnCount();
for (int column_itr = 0; column_itr < column_count; column_itr++) {
type::Value value(GetValue(column_itr));
value.SerializeTo(output);
}
output.WriteIntAt(
start, static_cast<int32_t>(output.Position() - start - sizeof(int32_t)));
}
void Tuple::SerializeWithHeaderTo(SerializeOutput &output) {
PL_ASSERT(tuple_schema_);
PL_ASSERT(tuple_data_);
size_t start = output.Position();
output.WriteInt(0); // reserve first 4 bytes for the total tuple size
const int column_count = tuple_schema_->GetColumnCount();
for (int column_itr = 0; column_itr < column_count; column_itr++) {
type::Value value = GetValue(column_itr);
value.SerializeTo(output);
}
int32_t serialized_size =
static_cast<int32_t>(output.Position() - start - sizeof(int32_t));
// write out the length of the tuple at start
output.WriteIntAt(start, serialized_size);
}
// Serialized only the tuples specified, along with header.
bool Tile::SerializeTuplesTo(SerializeOutput &output, Tuple *tuples,
int num_tuples) {
std::size_t pos = output.Position();
output.WriteInt(-1);
PL_ASSERT(!tuples[0].IsNull());
// Serialize the header
if (!SerializeHeaderTo(output)) return false;
output.WriteInt(static_cast<int32_t>(num_tuples));
for (int tuple_itr = 0; tuple_itr < num_tuples; tuple_itr++) {
tuples[tuple_itr].SerializeTo(output);
}
// Length prefix is non-inclusive
output.WriteIntAt(
pos, static_cast<int32_t>(output.Position() - pos - sizeof(int32_t)));
return true;
}
bool Tile::SerializeTo(SerializeOutput &output, oid_t num_tuples) {
/**
* The table is serialized as:
*
* [(int) total size]
* [(int) header size] [num columns] [column types] [column names]
* [(int) num tuples] [tuple data]
*
*/
// A placeholder for the total table size written at the end
std::size_t pos = output.Position();
output.WriteInt(-1);
// Serialize the header
if (!SerializeHeaderTo(output)) return false;
// Active tuple count
output.WriteInt(static_cast<int>(num_tuples));
oid_t written_count = 0;
TupleIterator tile_itr(this);
Tuple tuple(&schema);
while (tile_itr.Next(tuple) && written_count < num_tuples) {
tuple.SerializeTo(output);
++written_count;
}
tuple.SetNull();
PL_ASSERT(written_count == num_tuples);
// Length prefix is non-inclusive
int32_t sz = static_cast<int32_t>(output.Position() - pos - sizeof(int32_t));
PL_ASSERT(sz > 0);
output.WriteIntAt(pos, sz);
return true;
}