versaplexd/ischemabackend.cs

   1 /*
   2  * Versaplex:
   3  *   Copyright (C)2007-2008 Versabanq Innovations Inc. and contributors.
   4  *       See the included file named LICENSE for license information.
   5  */
   6 using System;
   7 using System.Collections.Generic;
   8
   9 // An interface to a Schemamatic schema backend.
  10 internal interface ISchemaBackend : IDisposable
  11 {
  12     // Update the backing store with all current elements.
  13     // If an element's text is empty, it will be deleted.
  14     VxSchemaErrors Put(VxSchema schema, VxSchemaChecksums sums, VxPutOpts opts);
  15
  16     // Get elements from the backing store.
  17     // If keys is non-empty, only returns the schema for listed keys.
  18     // If keys is empty, returns all schema elements.
  19     VxSchema Get(IEnumerable<string> keys);
  20
  21     // Gets the checksums for all elements from the backing store.
  22     VxSchemaChecksums GetChecksums();
  23
  24     // Removes the given elements from the schema.
  25     VxSchemaErrors DropSchema(IEnumerable<string> keys);
  26
  27     // Returns a blob of text that can be used with PutSchemaData to fill
  28     // the given table.
  29     // "seqnum" provides a hint about the priority of the table when batch
  30     // processing, and is used to locate the file on disk.
  31     // "where" is the body of a SQL "WHERE" clause, to limit the data
  32     // returned by the database, if applicable.
  33     // "replaces" is the list of replacements to be made on a field
  34     // "skipfields" is the list of fields to skip during export
  35     string GetSchemaData(string tablename, int seqnum, string where,
  36                          Dictionary<string,string> replaces,
  37                          List<string> skipfields);
  38
  39     // Delete all rows from the given table and replace them with the given
  40     // data.  text is an opaque hunk of text returned from GetSchemaData.
  41     // Seqnum provides a hint about the priority of the table when batch
  42     // processing, and is used to locate the file on disk.
  43     void PutSchemaData(string tablename, string text, int seqnum);
  44 }
  45
  46 [Flags]
  47 public enum VxPutOpts : int
  48 {
  49     None = 0,
  50     // If set, PutSchema will do potentially destructive things like
  51     // dropping a table in order to re-add it.
  52     Destructive = 0x1,
  53     // If set, PutSchema will not attempt to do any retries.
  54     NoRetry = 0x2,
  55     // If set and the element already exists, will create the new element
  56     // with a different name that doesn't already exist.
  57     // Currently only applies to the disk backend; other backends ignore this.
  58     IsBackup = 0x4,
  59 }
  60