Changes between Initial Version and Version 1 of PacpusTutorials/ManagingDbtFiles

Timestamp:

Apr 15, 2014, 3:20:17 PM (11 years ago)

Author:

DHERBOMEZ Gérald

Comment:

--

PacpusTutorials/ManagingDbtFiles

@@ +1 @@
+= Managing DBT Files with PACPUS =
+
+Pacpus framework offers a way to record data through DBT files. This is a binary format with timestamping functionalities. 
+
+== Important notes == 
+
+[=#point1 (1)] For this tutorial we will work with the trunk version of the pacpusframework repository. If you are using a specific tag or branch please change '''''trunk''''' by your specific '''''branch or tag path''''' for each link below. 
+
+[=#point2 (2)] To deal with DBT files you need to link you application with !FileLib library. The source code can be found in [source:trunk/src/FileLib this] folder.
+
+== How to create a new DBT file == 
+
+=== Step 1: identify the type and the structure of the data === 
+
+First you must identify the type of your data in this file [source:trunk/include/Pacpus/kernel/DbiteFileTypes.h DbiteFileTypes.h]. Remember note [#point1 (1)] and modify the path to fit with your installation of pacpusframework. If the type is already known by PACPUS, it is recommended to use it, else you need to create a new entry in this file. 
+
+For example, if you need to add a support BMP images, you can change this code block:
+
+{{{
+#!cpp
+enum BasicType
+{
+    FILE_IMAGE = 0
+    , FILE_CAN
+    , FILE_TEXT
+    , FILE_IMAGE3D
+    , FILE_DBT_UNKNOWN          ///< Unknown file type
+    , FILE_JPEG
+    , STREAM8POSITION = 100
+};
+}}}
+
+in:
+
+{{{
+#!cpp
+enum BasicType
+{
+    FILE_IMAGE = 0
+    , FILE_CAN
+    , FILE_TEXT
+    , FILE_IMAGE3D
+    , FILE_DBT_UNKNOWN          ///< Unknown file type
+    , FILE_JPEG
+    , FILE_MYSTRUCT                  ///< New MYSTRUCT file format (remark: the number of the ID will be 6 here) 
+    , STREAM8POSITION = 100
+};
+}}}
+
+''Warning, take care of using a free number in the file.''
+
+After this, you need to create the new structure of your data. It is a just a header file containing the C structure of the data. It is recommended to use standard types like uint32_t, int8_t, ... This types are available via [source:trunk/include/Pacpus/kernel/cstdint.h cstdint.h] file. 
+
+{{{
+#!cpp
+struct MYSTRUCT {
+  uint32_t data1;
+  int16_t data2; 
+  uint8_t data3;
+};
+}}}
+
+=== Step 2: creation of DBT file === 
+
+First we create an instance of pacpus::!DbiteFile.
+
+{{{
+#!cpp
+pacpus::DbiteFile dbtFile_; //!< DBT file.
+}}}
+
+After we open the DBT file in writing mode with this code: 
+
+{{{
+#!cpp
+try {
+    dbtFile_.open("my_struct_file.dbt", WriteMode, FILE_MYSTRUCT, sizeof(MYSTRUCT));
+} catch (DbiteException & e) {
+    cerr << "error opening dbt file: "<< kSickDbtFileName << ", " << e.what() << endl;
+    return;
+}
+}}}
+
+The my_struct_file.dbt file will be created in current path of the application (often it is the folder where you launched the application PacpusSensor). 
+