Quick Start - C

Dependencies

• CMake >=3.11
• Maven >=3.9.6
• GCC >=4.8.5
• Make >=4.3

Installation Method

Clone the source code from git:

git clone https://github.com/apache/tsfile.git

Run Maven to compile in the TsFile root directory:

mvn clean install -P with-cpp -DskipTests

If Maven is not installed, you can compile tsfile using the following command:

Linux or Macos:

mvnw clean install -P with-cpp -DskipTests

Windows:

mvnw.cmd clean install -P with-cpp -DskipTests

Directory Structure

• Include Directory: Located at tsfile/cpp/target/build/include/cwrapper, it contains header files for integration. Add this path to the compiler's include path (e.g., using -I flag).

• Lib Directory: At tsfile/cpp/target/build/lib, it holds compiled library files. Specify this path and library name when linking (e.g., using -L and -l flags).

CMake Integration

Add to your CMakeLists.txt:

find_library(TSFILE_LIB NAMES tsfile PATHS ${SDK_LIB} REQUIRED)
target_link_libraries(your_target ${TSFILE_LIB})

Note: Set ${SDK_LIB} to your TsFile library directory.

Writing Process

Construct TsFileWriter

    ERRNO code = 0;
    char* table_name = "table1";

    // Create table schema to describe a table in a tsfile.
    TableSchema table_schema;
    table_schema.table_name = strdup(table_name);
    table_schema.column_num = 3;
    table_schema.column_schemas =
        (ColumnSchema*)malloc(sizeof(ColumnSchema) * 3);
    table_schema.column_schemas[0] =
        (ColumnSchema){.column_name = strdup("id1"),
                     .data_type = TS_DATATYPE_STRING,
                     .column_category = TAG};
    table_schema.column_schemas[1] =
        (ColumnSchema){.column_name = strdup("id2"),
                     .data_type = TS_DATATYPE_STRING,
                     .column_category = TAG};
    table_schema.column_schemas[2] =
        (ColumnSchema){.column_name = strdup("s1"),
                     .data_type = TS_DATATYPE_INT32,
                     .column_category = FIELD};

    // Create a file with specify path to write tsfile.
    WriteFile file = write_file_new("test_c.tsfile", &code);
    HANDLE_ERROR(code);

    // Create tsfile writer with specify table schema.
    TsFileWriter writer = tsfile_writer_new(file, &table_schema, &code);
    HANDLE_ERROR(code);

Write Data

    // Create tablet to insert data.
    Tablet tablet =
        tablet_new((char*[]){"id1", "id2", "s1"},
                   (TSDataType[]){TS_DATATYPE_STRING, TS_DATATYPE_STRING,
                                  TS_DATATYPE_INT32},
                   3, 5);

    for (int row = 0; row < 5; row++) {
        Timestamp timestamp = row;
        tablet_add_timestamp(tablet, row, timestamp);
        tablet_add_value_by_name_string(tablet, row, "id1", "id_field_1");
        tablet_add_value_by_name_string(tablet, row, "id2", "id_field_2");
        tablet_add_value_by_name_int32_t(tablet, row, "s1", row);
    }

    // Write tablet data.
    HANDLE_ERROR(tsfile_writer_write(writer, tablet));

    // Free tablet.
    free_tablet(&tablet);

    // Free table schema we used before.
    free_table_schema(table_schema);

Close File

    // Close writer.
    HANDLE_ERROR(tsfile_writer_close(writer));

    // Close write file after closing writer.
    free_write_file(&file);

Sample Code

The sample code of using these interfaces is in https://github.com/apache/tsfile/blob/develop/cpp/examples/c_examples/demo_write.c

Reading Process

Construct TsFileReader

    ERRNO code = 0;
    char* table_name = "table1";

    // Create tsfile reader with specify tsfile's path
    TsFileReader reader = tsfile_reader_new("test_c.tsfile", &code);
    HANDLE_ERROR(code);

Construct Query

    ResultSet ret = tsfile_query_table(
        reader, table_name, (char*[]){"id1", "id2", "s1"}, 3, 0, 10, &code);
    HANDLE_ERROR(code);

    if (ret == NULL) {
        HANDLE_ERROR(RET_INVALID_QUERY);
    }

Query Data

    // Get query result metadata: column name and datatype
    ResultSetMetaData metadata = tsfile_result_set_get_metadata(ret);
    int column_num = tsfile_result_set_metadata_get_column_num(metadata);

    for (int i = 1; i <= column_num; i++) {
        printf("column:%s, datatype:%d\n", tsfile_result_set_metadata_get_column_name(metadata, i),
               tsfile_result_set_metadata_get_data_type(metadata, i));
    }

    // Get data by column name or index.
    while (tsfile_result_set_next(ret, &code) && code == RET_OK) {
        // Timestamp at column 1 and column index begin from 1.
        Timestamp timestamp =
            tsfile_result_set_get_value_by_index_int64_t(ret, 1);
        printf("%ld\n", timestamp);
        for (int i = 1; i <= column_num; i++) {
            if (tsfile_result_set_is_null_by_index(ret, i)) {
                printf(" null ");
            } else {
                switch (tsfile_result_set_metadata_get_data_type(metadata, i)) {
                    case TS_DATATYPE_BOOLEAN:
                        printf("%d\n", tsfile_result_set_get_value_by_index_bool(
                                         ret, i));
                        break;
                    case TS_DATATYPE_INT32:
                        printf("%d\n",
                               tsfile_result_set_get_value_by_index_int32_t(ret,
                                                                            i));
                        break;
                    case TS_DATATYPE_INT64:
                        printf("%ld\n",
                               tsfile_result_set_get_value_by_index_int64_t(ret,
                                                                            i));
                        break;
                    case TS_DATATYPE_FLOAT:
                        printf("%f\n", tsfile_result_set_get_value_by_index_float(
                                         ret, i));
                        break;
                    case TS_DATATYPE_DOUBLE:
                        printf("%lf\n",
                               tsfile_result_set_get_value_by_index_double(ret,
                                                                           i));
                        break;
                    case TS_DATATYPE_STRING:
                        printf("%s\n",
                               tsfile_result_set_get_value_by_index_string(ret,
                                                                           i));
                        break;
                    default:
                        printf("unknown_type");
                        break;
                }
            }
        }
    }

    // Free query meta data
    free_result_set_meta_data(metadata);

    // Free query handler.
    free_tsfile_result_set(&ret);

Close File

    // Close tsfile reader.
    tsfile_reader_close(reader);

Sample Code

The sample code of using these interfaces is in https://github.com/apache/tsfile/blob/develop/cpp/examples/c_examples/demo_read.c