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#include "komfydb/storage/heap_page.h"
#include "komfydb/common/int_field.h"
#include "komfydb/common/string_field.h"
#include "komfydb/config.h"
#include "komfydb/utils/status_macros.h"
namespace {
using namespace komfydb::common;
absl::StatusOr<bool> TuplePresent(std::vector<uint8_t>& header, int i) {
if (i / 8 >= header.size() || i < 0)
return absl::InvalidArgumentError("Index out of range");
return header[i / 8] & (1 << (i % 8));
}
std::unique_ptr<IntField> ParseInt(std::vector<uint8_t>& data, int& data_idx) {
std::unique_ptr<IntField> field =
std::make_unique<IntField>(*((int*)&data[data_idx]));
data_idx += Type::INT_LEN;
return field;
}
std::unique_ptr<StringField> ParseString(std::vector<uint8_t>& data,
int& data_idx) {
std::unique_ptr<StringField> value =
std::make_unique<StringField>((char*)&data[data_idx]);
data_idx += Type::STR_LEN;
return value;
}
void DumpString(Field* field, std::vector<uint8_t>& result) {
std::string data;
field->GetValue(data);
int padding = Type::STR_LEN - data.size();
result.insert(result.end(), data.begin(), data.end());
result.insert(result.end(), padding, '\0');
}
void DumpInt(Field* field, std::vector<uint8_t>& result) {
int data;
field->GetValue(data);
uint8_t* bytes = reinterpret_cast<uint8_t*>(&data);
result.insert(result.end(), bytes, bytes + sizeof(data));
}
} // namespace
namespace komfydb::storage {
absl::StatusOr<std::unique_ptr<HeapPage>> HeapPage::Create(
PageId pid, TupleDesc* td, std::vector<uint8_t>& data) {
int n_slots = (CONFIG_PAGE_SIZE * 8) / (td->GetSize() * 8 + 1);
int header_len = (n_slots + 7) / 8;
int n_fields = td->Length();
int data_idx = header_len;
std::vector<uint8_t> header;
std::vector<Record> records;
header.insert(header.end(), data.begin(), data.begin() + header_len);
for (int i = 0; i < n_slots; i++) {
Record record(td, pid, i);
for (int j = 0; j < n_fields; j++) {
ASSIGN_OR_RETURN(Type field_type, td->GetFieldType(j));
if (field_type.GetValue() == Type::INT) {
RETURN_IF_ERROR(record.SetField(j, ParseInt(data, data_idx)));
} else if (field_type.GetValue() == Type::STRING) {
RETURN_IF_ERROR(record.SetField(j, ParseString(data, data_idx)));
}
}
records.push_back(std::move(record));
}
return std::unique_ptr<HeapPage>(
new HeapPage(pid, td, header, std::move(records), n_slots));
}
PageId HeapPage::GetId() {
return pid;
}
// std::optional<TransactionId> HeapPage::DirtiedBy() {
// }
// void HeapPage::MarkDirty(bool dirty, TransactionId tid) {
// }
absl::StatusOr<std::vector<uint8_t>> HeapPage::GetPageData() {
// TODO: uncomment when DirtiedBy is implemented
// if (!DirtiedBy())
// return old_data;
std::vector<uint8_t> result = header;
int tuple_len = td->Length();
int record_idx = 0;
for (int i = 0; i < num_slots; i++) {
ASSIGN_OR_RETURN(bool tuple_present, TuplePresent(header, i));
if (!tuple_present) {
result.insert(result.end(), td->GetSize(), '\0');
continue;
}
Record& record = records[record_idx];
record_idx++;
for (int j = 0; j < tuple_len; j++) {
ASSIGN_OR_RETURN(Type field_type, td->GetFieldType(j));
ASSIGN_OR_RETURN(Field * field, record.GetField(j));
if (field_type.GetValue() == Type::STRING)
DumpString(field, result);
else if (field_type.GetValue() == Type::INT)
DumpInt(field, result);
}
}
result.insert(result.end(), CONFIG_PAGE_SIZE - result.size(), '\0');
return result;
}
absl::StatusOr<std::unique_ptr<Page>> HeapPage::GetBeforeImage() {
absl::MutexLock l(&old_data_lock);
ASSIGN_OR_RETURN(std::unique_ptr<HeapPage> result, Create(pid, td, old_data));
return result;
}
absl::Status HeapPage::SetBeforeImage() {
absl::MutexLock l(&old_data_lock);
ASSIGN_OR_RETURN(old_data, GetPageData());
return absl::OkStatus();
}
std::vector<Record>& HeapPage::GetRecords() {
return records;
}
}; // namespace komfydb::storage
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