上载过程中的事件

下面的伪代码说明了如何调用上载事件和上载脚本。伪代码使用以下约定：

A script is real 这表示脚本被定义为真实脚本，将在同步过程中对统一数据库执行。
A script is defined as an ignored script 这表示使用了 "--{ml_ignore}" 将脚本定义为忽略的脚本。
A script is defined 这表示脚本被定义为真实脚本或忽略的脚本
A script is not defined 这表示没有为事件定义任何脚本。如果这是必需的脚本但不想使用该脚本，则必须忽略脚本。

这些事件在完整事件模型中的上载位置发生。请参见MobiLink 事件概述。

上载概述

------------------------------------------------------
upload
------------------------------------------------------

begin_upload // Connection event
for each table being synchronized {
  begin_upload // Table event
}
  handle_UploadData
  for each table being synchronized {
    begin_upload_rows
    for each uploaded INSERT or UPDATE for this table {
      if( INSERT ) {
        <upload_inserted_row>
      }
      if( UPDATE ) {
        <upload_updated_row>
      }
    }
    end_upload_rows
  }
  for each table being synchronized IN REVERSE ORDER {
    begin_upload_deletes
    for each uploaded DELETE for this table {
      <upload_deleted_row>
    }
    end_upload_deletes
  }
 
For each table being synchronized {
  if( begin_upload table script was processed ) {
    end_upload // Table event
  }
}
if( begin_upload connection script was processed ) {
  end_upload // Connection event

  for each table being synchronized {
    upload_statistics  // Table event.
  }
    upload_statistics  // Connection event.

  COMMIT

上载插入

------------------------------------------------------
<upload_inserted_row>
------------------------------------------------------
// NOTES:
// - Only table scripts for the current table are involved.

 ConflictsAreExpected <- (
    upload_new_row_insert script is defined or
    upload_old_row_insert script is defined )
if( upload_insert script is real ) {
    upload_insert
} else if( ConflictsAreExpected and
    upload_update script is not defined and
    upload_insert script is not defined and
    upload_delete script is not defined ) {
    // Forced conflict which is deprecated
    if( upload_new_row_insert script is real ) {
        upload_new_row_insert
        resolve_conflict
    } else if( upload_new_row_insert is defined as an ignored script ) {
        // Ignore this insert
    } else {
        error
    }
} else if( handle_uploadData script is real or
    upload_insert script is defined as an ignored script ) {
    // Ignore the insert. (Only ignored in SQL, possibly handled by handle_uploadData.)
} else {
    error
}

上载更新

------------------------------------------------------
upload_updated_row
------------------------------------------------------
// NOTES:
// - Only table scripts for the current table are involved.
// - Both the old (original) and new rows are uploaded for
//   each update.

 ConflictsAreExpected <- (
   upload_new_row_insert script is defined or
   upload_old_row_insert script is defined )
Conflicted <- FALSE
if( upload_update script is real ) {
    if( upload_fetch script is real ) {
        if( ConflictsAreExpected ) {
            FETCH using upload_fetch INTO current_row
            if( current_row <> old row ) {
                Conflicted <- TRUE
            } else {
                upload_update
            }
        } else {
            error
        } 
    } else if( upload_fetch script is not defined ) {
        if( ConflictsAreExpected ) {
            // This conflict detection approach is deprecated
            upload_update
            if( number of affected rows is 0 ) {
                Conflicted <- TRUE
            }
        } else {
            // No conflict detection and resolution by the MobiLink server
            // The upload_update script should handle conflict detection and resolution
            upload_update
        }
    } else {
	// the upload_ftech script cannot defined as an ignored script
	error
    } 
} else if( ConflictsAreExpected and
    upload_update script is not defined and
    upload_insert script is not defined and
    upload_delete script is not defined ) {
    // Forced conflict which is deprecated
    Conflicted <- TRUE
} else if( handle_uploadData script is defined or upload_update script is defined as an ignored script ) {
    // Ignore the upload update (Only ignored in SQL, possibly handled by handle_uploadData.)
} else {
    error
}
if( Conflicted ) {
    if( upload_old_row_insert script is real ) {
        upload_old_row_insert
    } else if( upload_old_row_insert script is defined as ignored script ) {
        // Ignore the old value
    } else {
        error
    }
    if( upload_new_row_insert script is real ) {
        upload_new_row_insert
    } else if( upload_new_row_insert script is defined as ignored script ) {
        // Ignore the new value
    } else {
        error
    }
    if( no error ) {
        resolve_conflict
    }
}

上载删除

------------------------------------------------------
upload_deleted_row
------------------------------------------------------
// NOTES:
// - Only table scripts for the current table are involved.

  ConflictsAreExpected <- (
    upload_new_row_insert script is defined or
    upload_old_row_insert script is defined )
if( upload_delete is real ) {
    upload_delete
} else if( ConflictsAreExpected
    and upload_update script is not defined
    and upload_insert script is not defined
    and upload_delete script is not defined ) {
    // Forced conflict which is deprecated
    if( upload_old_row_insert is real ) {
        upload_old_row_insert
        resolve_conflict
    } else if( upload_old_row_insert is defined as an ignored script ) {
        // Ignore the delete
    } else {
        error
    }
} else if( handle_UploadData script is real or
    upload_delete script is defined as an ignored script ) {
    // Ignore this delete. (Only ignored in SQL, possibly handled by handle_uploadData.)
} else {
    error
}

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