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# 接口定义
## 写入接口
### ITsFileWriter
用于写入数据至 tsfile
```Java
interface ITsFileWriter extends AutoCloseable {
// 写入数据
void write(Tablet tablet);
// 关闭写入
void close();
}
```
### TsFileWriterBuilder
用于构造 ITsFileWriter
```Java
class TsFileWriterBuilder {
// 构建 ITsFileWriter 对象
public ITsFileWriter build();
// 目标文件
public TsFileWriterBuilder file(File file);
// 用于构造表结构
public TsFileWriterBuilder tableSchema(TableSchema schema);
// 用于限制对象的内存大小
public TsFileWriterBuilder memoryThreshold(long memoryThreshold);
}
```
### TableSchema
描述表 schema 的数据结构
```Java
class TableSchema {
// 构造函数
public TableSchema(String tableName, List<ColumnSchema> columnSchemaList);
}
class ColumnSchema {
// 构造函数
public ColumnSchema(String columnName, TSDataType dataType, ColumnCategory columnCategory);
// 获取列名
public String getColumnName();
// 获取列的数据类型
public TSDataType getDataType();
// 获取列的类别
public Tablet.ColumnCategory getColumnCategory();
}
class ColumnSchemaBuilder {
// 构建 ColumnSchema 对象
public ColumnSchema build();
// 列名
public ColumnSchemaBuilder name(String columnName);
// 列的数据类型
public ColumnSchemaBuilder dataType(TSDataType columnType);
// 列类别
public ColumnSchemaBuilder category(ColumnCategory columnCategory);
// 支持的数据类型
enum TSDataType {
BOOLEAN,
INT32,
INT64,
FLOAT,
DOUBLE,
TIMESTAMP,
TEXT,
DATE,
BLOB,
STRING;
}
// 支持的列类别
enum ColumnCategory {
TAG,
FIELD
}
}
```
### Tablet
写入的列式内存结构
```Java
class Tablet {
// 构造函数
public Tablet(List<String> columnNameList, List<TSDataType> dataTypeList);
public Tablet(List<String> columnNameList, List<TSDataType> dataTypeList, int maxRowNum);
// 添加时间戳的接口
void addTimestamp(int rowIndex, long timestamp);
// 添加值的接口
// 根据列名添加值
void addValue(int rowIndex, String columnName, int val);
void addValue(int rowIndex, String columnName, long val);
void addValue(int rowIndex, String columnName, float val);
void addValue(int rowIndex, String columnName, double val);
void addValue(int rowIndex, String columnName, boolean val);
void addValue(int rowIndex, String columnName, String val);
void addValue(int rowIndex, String columnName, byte[] val);
void addValue(int rowIndex, String columnName, LocalDate val);
// 根据索引位置添加值
void addValue(int rowIndex, int columnIndex, int val);
void addValue(int rowIndex, int columnIndex, long val);
void addValue(int rowIndex, int columnIndex, float val);
void addValue(int rowIndex, int columnIndex, double val);
void addValue(int rowIndex, int columnIndex, boolean val);
void addValue(int rowIndex, int columnIndex, String val);
void addValue(int rowIndex, int columnIndex, byte[] val);
void addValue(int rowIndex, int columnIndex, LocalDate val);
}
```
## 查询接口
### ITsFileReader
用于查询 tsfile 中的数据
```Java
interface ITsFileReader extends AutoCloseable {
// 用于执行查询并返回结果
ResultSet query(String tableName, List<String> columnNames, long startTime, long endTime);
// 返回tsfile中名为tableName的表的架构
Optional<TableSchema> getTableSchemas(String tableName);
// 检索ts文件中所有表的架构信息
List<TableSchema> getAllTableSchema();
// 关闭查询
void close();
}
```
### TsFileReaderBuilder
用于构建 ITsFileReader
```Java
class TsFileReaderBuilder {
// 构建 ITsFileReader 对象
public ITsFileReader build();
// 目标文件
public TsFileReaderBuilder file(File file);
}
```
### ResultSet
查询的结果集
```Java
interface ResultSet extends AutoCloseable {
// 将光标移动到下一行并返回是否还有数据
boolean next();
// 获取当前行和某一列的值
int getInt(String columnName);
int getInt(int columnIndex);
long getLong(String columnName);
long getLong(int columnIndex);
float getFloat(String columnName);
float getFloat(int columnIndex);
double getDouble(String columnName);
double getDouble(int columnIndex);
boolean getBoolean(String columnName);
boolean getBoolean(int columnIndex);
String getString(String columnName);
String getString(int columnIndex);
LocalDate getDate(String columnName);
LocalDate getDate(int columnIndex);
byte[] getBinary(String columnName);
byte[] getBinary(int columnIndex);
// 确定当前行中的列是否为NULL
boolean isNull(String columnName);
boolean isNull(int columnIndex);
// 关闭当前结果集
void close();
// 获取结果集的表头
ResultSetMetadata getMetadata();
}
```
### ResultSetMetadata
用于获取结果集的元数据
```Java
interface ResultSetMetadata {
// 获取结果集第N列的列名
String getColumnName(int columnIndex);
// 获取结果集第N列的数据类型
TSDataType getColumnType(int columnIndex);
}
```