blob.cpp

/*
 * PROGRAM: InterBase layered support library
 * MODULE: blob.cpp
 * DESCRIPTION: Dynamic blob support
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 *
 * 2001.09.10 Claudio Valderrama: get_name() was preventing the API calls
 * isc_blob_default_desc, isc_blob_lookup_desc & isc_blob_set_desc
 * from working properly with dialect 3 names. Therefore, incorrect names
 * could be returned or a lookup for a blob field could fail. In addition,
 * a possible buffer overrun due to unchecked bounds was closed. The fc
 * get_name() as been renamed copy_exact_name().
 *
*/

#include"firebird.h"
#include"firebird/Message.h"
#include"ibase.h"
#include"../jrd/intl.h"
#include"../yvalve/blob_proto.h"
#include"../yvalve/YObjects.h"
#include"../common/StatusArg.h"
#include"../common/utils_proto.h"
#include"../jrd/constants.h"

usingnamespaceFirebird;

staticvoidcopy_exact_name (const UCHAR*, UCHAR*, SSHORT);
static ISC_STATUS error(ISC_STATUS* status, const Arg::StatusVector& v);


void API_ROUTINE isc_blob_default_desc(ISC_BLOB_DESC* desc,
const UCHAR* relation_name,
const UCHAR* field_name)
{
/**************************************
 *
 * i s c _ b l o b _ d e f a u l t _ d e s c
 *
 **************************************
 *
 * Functional description
 *
 * This function will set the default
 * values in the blob_descriptor.
 *
 **************************************/

 desc->blob_desc_subtype = isc_blob_text;
 desc->blob_desc_charset = CS_dynamic;
 desc->blob_desc_segment_size = 80;

copy_exact_name(field_name, desc->blob_desc_field_name, sizeof(desc->blob_desc_field_name));
copy_exact_name(relation_name, desc->blob_desc_relation_name, sizeof(desc->blob_desc_relation_name));
}


ISC_STATUS API_ROUTINE isc_blob_gen_bpb(ISC_STATUS* status,
const ISC_BLOB_DESC* to_desc,
const ISC_BLOB_DESC* from_desc,
 USHORT bpb_buffer_length,
 UCHAR* bpb_buffer,
 USHORT* bpb_length)
{
/**************************************
 *
 * i s c _ b l o b _ g e n _ b p b
 *
 **************************************
 *
 * Functional description
 *
 * This function will generate a bpb
 * given a to_desc and a from_desc
 * which contain the subtype and
 * character set information.
 *
 **************************************/
if (bpb_buffer_length < 17)
returnerror(status, Arg::Gds(isc_random) << Arg::Str("BPB buffer too small"));

 UCHAR* p = bpb_buffer;
 *p++ = isc_bpb_version1;
 *p++ = isc_bpb_target_type;
 *p++ = 2;
 *p++ = (UCHAR)to_desc->blob_desc_subtype;
 *p++ = (UCHAR)(to_desc->blob_desc_subtype >> 8);
 *p++ = isc_bpb_source_type;
 *p++ = 2;
 *p++ = (UCHAR)from_desc->blob_desc_subtype;
 *p++ = (UCHAR)(from_desc->blob_desc_subtype >> 8);
 *p++ = isc_bpb_target_interp;
 *p++ = 2;
 *p++ = (UCHAR)to_desc->blob_desc_charset;
 *p++ = (UCHAR)(to_desc->blob_desc_charset >> 8);
 *p++ = isc_bpb_source_interp;
 *p++ = 2;
 *p++ = (UCHAR)from_desc->blob_desc_charset;
 *p++ = (UCHAR)(from_desc->blob_desc_charset >> 8);

 *bpb_length = p - bpb_buffer;

returnerror(status, Arg::Gds(FB_SUCCESS));
}


// Lookup the blob subtype, character set and segment size information from the metadata,
// given a relation/procedure name and column/parameter name.
// It will fill in the information in the BLOB_DESC.
voidiscBlobLookupDescImpl(Why::YAttachment* attachment, Why::YTransaction* transaction,
const UCHAR* relationName, const UCHAR* fieldName, ISC_BLOB_DESC* desc, UCHAR* global)
{
 LocalStatus status;
 CheckStatusWrapper statusWrapper(&status);

copy_exact_name(fieldName, desc->blob_desc_field_name, sizeof(desc->blob_desc_field_name));
copy_exact_name(relationName, desc->blob_desc_relation_name, sizeof(desc->blob_desc_relation_name));

bool flag = false;

// Shared by both queries.
FB_MESSAGE(OutputMessage, CheckStatusWrapper,
 (FB_INTEGER, fieldSubType)
 (FB_INTEGER, segmentLength)
 (FB_INTEGER, characterSetId)
 ) outputMessage(&statusWrapper, MasterInterfacePtr());

 { // scope
constexprauto sql = R"""(
 select f.rdb$field_sub_type,
 f.rdb$segment_length,
 f.rdb$character_set_id
 from rdb$relation_fields rf
 join rdb$fields f
 on f.rdb$field_name = rf.rdb$field_source
 where rf.rdb$relation_name = ? and
 rf.rdb$field_name = ?
)""";

FB_MESSAGE(InputMessage, CheckStatusWrapper,
 (FB_VARCHAR(MAX_SQL_IDENTIFIER_LEN), relationName)
 (FB_VARCHAR(MAX_SQL_IDENTIFIER_LEN), fieldName)
 ) inputMessage(&statusWrapper, MasterInterfacePtr());
 inputMessage.clear();

 inputMessage->relationNameNull = FB_FALSE;
 inputMessage->relationName.set((constchar*) relationName);

 inputMessage->fieldNameNull = FB_FALSE;
 inputMessage->fieldName.set((constchar*) fieldName);

auto resultSet = makeNoIncRef(attachment->openCursor(&statusWrapper, transaction, 0, sql,
 SQL_DIALECT_CURRENT, inputMessage.getMetadata(), inputMessage.getData(),
 outputMessage.getMetadata(), nullptr, 0));
 status.check();

if (resultSet->fetchNext(&statusWrapper, outputMessage.getData()) == IStatus::RESULT_OK)
 {
 flag = true;

 desc->blob_desc_subtype = outputMessage->fieldSubTypeNull ? 0 : outputMessage->fieldSubType;
 desc->blob_desc_charset = outputMessage->characterSetIdNull ? 0 : outputMessage->characterSetId;
 desc->blob_desc_segment_size = outputMessage->segmentLengthNull ? 0 : outputMessage->segmentLength;
 }

 status.check();
 }

if (!flag)
 {
constexprauto sql = R"""(
 select f.rdb$field_sub_type,
 f.rdb$segment_length,
 f.rdb$character_set_id
 from rdb$procedure_parameters pp
 join rdb$fields f
 on f.rdb$field_name = pp.rdb$field_source
 where pp.rdb$procedure_name = ? and
 pp.rdb$parameter_name = ? and
 pp.rdb$package_name is null
)""";

FB_MESSAGE(InputMessage, CheckStatusWrapper,
 (FB_VARCHAR(MAX_SQL_IDENTIFIER_LEN), procedureName)
 (FB_VARCHAR(MAX_SQL_IDENTIFIER_LEN), fieldName)
 ) inputMessage(&statusWrapper, MasterInterfacePtr());
 inputMessage.clear();

 inputMessage->procedureNameNull = FB_FALSE;
 inputMessage->procedureName.set((constchar*) relationName);

 inputMessage->fieldNameNull = FB_FALSE;
 inputMessage->fieldName.set((constchar*) fieldName);

auto resultSet = makeNoIncRef(attachment->openCursor(&statusWrapper, transaction, 0, sql,
 SQL_DIALECT_CURRENT, inputMessage.getMetadata(), inputMessage.getData(),
 outputMessage.getMetadata(), nullptr, 0));
 status.check();

if (resultSet->fetchNext(&statusWrapper, outputMessage.getData()) == IStatus::RESULT_OK)
 {
 flag = true;

 desc->blob_desc_subtype = outputMessage->fieldSubTypeNull ? 0 : outputMessage->fieldSubType;
 desc->blob_desc_charset = outputMessage->characterSetIdNull ? 0 : outputMessage->characterSetId;
 desc->blob_desc_segment_size = outputMessage->segmentLengthNull ? 0 : outputMessage->segmentLength;
 }

 status.check();
 }

if (!flag)
 {
 (Arg::Gds(isc_fldnotdef) <<
Arg::Str((constchar*)(desc->blob_desc_field_name)) <<
Arg::Str((constchar*)(desc->blob_desc_relation_name))).raise();
 }

if (global)
copy_exact_name(fieldName, global, sizeof(desc->blob_desc_field_name));
}


ISC_STATUS API_ROUTINE isc_blob_set_desc(ISC_STATUS* status,
const UCHAR* relation_name,
const UCHAR* field_name,
 SSHORT subtype,
 SSHORT charset,
 SSHORT segment_size,
 ISC_BLOB_DESC* desc)
{
/**************************************
 *
 * i s c _ b l o b _ s e t _ d e s c
 *
 **************************************
 *
 * Functional description
 *
 * This routine will set the subtype
 * and character set information in the
 * BLOB_DESC based on the information
 * specifically passed in by the user.
 *
 **************************************/

copy_exact_name(field_name, desc->blob_desc_field_name, sizeof(desc->blob_desc_field_name));
copy_exact_name(relation_name, desc->blob_desc_relation_name, sizeof(desc->blob_desc_relation_name));

 desc->blob_desc_subtype = subtype;
 desc->blob_desc_charset = charset;
 desc->blob_desc_segment_size = segment_size;

returnerror(status, Arg::Gds(FB_SUCCESS));
}




staticvoidcopy_exact_name (const UCHAR* from, UCHAR* to, SSHORT bsize)
{
/**************************************
 *
 * c o p y _ e x a c t _ n a m e
 *
 **************************************
 *
 * Functional description
 * Copy null terminated name ot stops at bsize - 1.
 *
 **************************************/
const UCHAR* const from_end = from + bsize - 1;
 UCHAR* to2 = to - 1;
while (*from && from < from_end)
 {
if (*from != '') {
 to2 = to;
 }
 *to++ = *from++;
 }
 *++to2 = 0;
}


static ISC_STATUS error(ISC_STATUS* status, const Arg::StatusVector& v)
{
/**************************************
 *
 * e r r o r
 *
 **************************************
 *
 * Functional description
 * Stuff a status vector.
 *
 **************************************/
return v.copyTo(status);
}