Github user ajantha-bhat commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2345#discussion_r191110226
--- Diff:
store/sdk/src/main/java/org/apache/carbondata/sdk/file/CarbonReader.java ---
@@ -101,6 +108,43 @@ public static CarbonReaderBuilder builder(String
tablePath, String tableName) {
return reader.readSchema();
}
+ /**
+ * Read carbonindex file and return the schema
+ * @param indexFilePath complete path including index file name
+ * @return null, if the index file is not present in the path.
+ * List<ColumnSchema> from the index file.
+ * @throws IOException
+ */
+ public static List<ColumnSchema> readSchemaInIndexFile(String
indexFilePath) throws IOException {
+ CarbonFile indexFile =
+ FileFactory.getCarbonFile(indexFilePath,
FileFactory.getFileType(indexFilePath));
+ if (!indexFile.getName().endsWith(CarbonTablePath.INDEX_FILE_EXT)) {
+ throw new IOException("Not an index file name");
+ }
+ // read schema from the first index file
+ DataInputStream dataInputStream =
+ FileFactory.getDataInputStream(indexFilePath,
FileFactory.getFileType(indexFilePath));
+ byte[] bytes = new byte[(int) indexFile.getSize()];
+ try {
+ //get the file in byte buffer
+ dataInputStream.readFully(bytes);
+ CarbonIndexFileReader indexReader = new CarbonIndexFileReader();
+ // read from byte buffer.
+ indexReader.openThriftReader(bytes);
+ // get the index header
+ org.apache.carbondata.format.IndexHeader readIndexHeader =
indexReader.readIndexHeader();
+ List<ColumnSchema> columnSchemaList = new ArrayList<ColumnSchema>();
+ List<org.apache.carbondata.format.ColumnSchema> table_columns =
+ readIndexHeader.getTable_columns();
+ for (org.apache.carbondata.format.ColumnSchema columnSchema:
table_columns) {
--- End diff --
OK.
---
