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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License
     15  */
     16 
     17 package com.android.providers.contacts.database;
     18 
     19 import com.android.providers.contacts.util.NeededForTesting;
     20 
     21 import android.database.Cursor;
     22 import android.util.Log;
     23 
     24 /**
     25  * Static methods for database operations.
     26  */
     27 public class MoreDatabaseUtils {
     28 
     29     /**
     30      * Builds a CREATE INDEX ddl statement for a given table and field.
     31      *
     32      * @param table The table name.
     33      * @param field The field to index.
     34      * @return The create index sql statement.
     35      */
     36     public static String buildCreateIndexSql(String table, String field) {
     37         return "CREATE INDEX " + buildIndexName(table, field) + " ON " + table
     38                 + "(" + field + ")";
     39     }
     40 
     41     /**
     42      * Builds a DROP INDEX ddl statement for a given table and field.
     43      *
     44      * @param table The table name that was originally used to create the index.
     45      * @param field The field that was originally used to create the index.
     46      * @return The drop index sql statement.
     47      */
     48     @NeededForTesting
     49     public static String buildDropIndexSql(String table, String field) {
     50         return "DROP INDEX IF EXISTS " + buildIndexName(table, field);
     51     }
     52 
     53     /**
     54      * The index is created with a name using the following convention:
     55      * <p>
     56      * [table name]_[field name]_index
     57      */
     58     public static String buildIndexName(String table, String field) {
     59         return table + "_" + field + "_index";
     60     }
     61 
     62     /**
     63      * Build a bind arg where clause.
     64      * <p>
     65      * e.g. Calling this method with value of 4 results in:
     66      * <p>
     67      * "?,?,?,?"
     68      *
     69      * @param numArgs The number of arguments.
     70      * @return A string that can be used for bind args in a sql where clause.
     71      */
     72     @NeededForTesting
     73     public static String buildBindArgString(int numArgs) {
     74         final StringBuilder sb = new StringBuilder();
     75         String delimiter = "";
     76         for (int i = 0; i < numArgs; i++) {
     77             sb.append(delimiter).append("?");
     78             delimiter = ",";
     79         }
     80         return sb.toString();
     81     }
     82 
     83     /** Debug utility that dumps a cursor on logcat. */
     84     public static final void dumpCursor(String logTag, String name, Cursor c) {
     85         Log.d(logTag, "Dumping cursor " + name + " containing " + c.getCount() + " rows");
     86 
     87         // Dump the column names.
     88         final StringBuilder sb = new StringBuilder();
     89         for (int i = 0; i < c.getColumnCount(); i++) {
     90             if (sb.length() > 0) sb.append(" ");
     91             sb.append(c.getColumnName(i));
     92         }
     93         Log.d(logTag, sb.toString());
     94 
     95         // Dump the values.
     96         c.moveToPosition(-1);
     97         while (c.moveToNext()) {
     98             sb.setLength(0);
     99             sb.append("row#");
    100             sb.append(c.getPosition());
    101 
    102             for (int i = 0; i < c.getColumnCount(); i++) {
    103                 sb.append(" ");
    104 
    105                 String s = c.getString(i);
    106                 sb.append(s == null ? "{null}" : s.replaceAll("\\s", "{space}"));
    107             }
    108             Log.d(logTag, sb.toString());
    109         }
    110     }
    111 }
    112