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Fixed buffer length when fetching binary fields as streams

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This commit is contained in:
Jenny Tam 2020-10-23 13:13:29 -07:00
parent dff66a7982
commit 6b1923cde2
3 changed files with 76 additions and 37 deletions
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23
source/shared/core_results.cpp
View file

@ -882,7 +882,7 @@ SQLRETURN binary_to_string( _Inout_ SQLCHAR* field_data, _Inout_ SQLLEN& read_so
_In_ SQLLEN buffer_length, _Inout_ SQLLEN* out_buffer_length,
_Inout_ sqlsrv_error_auto_ptr& out_error )
{
// hex characters for the conversion loop below
// The hex characters for the conversion loop below
static char hex_chars[] = "0123456789ABCDEF";
SQLSRV_ASSERT( out_error == 0, "Pending error for sqlsrv_buffered_results_set::binary_to_string" );
@ -892,18 +892,19 @@ SQLRETURN binary_to_string( _Inout_ SQLCHAR* field_data, _Inout_ SQLLEN& read_so
// Set the amount of space necessary for null characters at the end of the data.
SQLSMALLINT extra = sizeof(Char);
// TO convert a binary to a system string or a binary to a wide string, the buffer size minur extra
// is expected to be multiples of 2 or 4 (depending on Char), but calculating to_copy_hex below
// TO convert a binary to a system string or a binary to a wide string, the buffer size minus
// 'extra' is ideally multiples of 2 or 4 (depending on Char), but calculating to_copy_hex below
// takes care of this.
// all fields will be treated as ODBC returns varchar(max) fields:
// All fields will be treated as ODBC returns varchar(max) fields:
// the entire length of the string is returned the first
// call in out_buffer_len. Successive calls return how much is
// left minus how much has already been read by previous reads
// *2 is for each byte to hex conversion and * extra is for either system or wide string allocation
// *2 is for each byte to hex conversion and * extra is for either system
// or wide string allocation
*out_buffer_length = (*reinterpret_cast<SQLLEN*>( field_data - sizeof( SQLULEN )) - read_so_far) * 2 * extra;
// copy as much as we can into the buffer
// Will copy as much as we can into the buffer
SQLLEN to_copy;
if( buffer_length < *out_buffer_length + extra ) {
to_copy = (buffer_length - extra);
@ -916,13 +917,13 @@ SQLRETURN binary_to_string( _Inout_ SQLCHAR* field_data, _Inout_ SQLLEN& read_so
to_copy = *out_buffer_length;
}
// if there are bytes to copy as hex
// If there are bytes to copy as hex
if( to_copy > 0 ) {
// quick hex conversion routine
Char* h = reinterpret_cast<Char*>( buffer );
BYTE* b = reinterpret_cast<BYTE*>( field_data + read_so_far );
Char* h = reinterpret_cast<Char*>(buffer);
BYTE* b = reinterpret_cast<BYTE*>(field_data + read_so_far);
// to_copy contains the number of bytes to copy, so we divide the number in half (or quarter)
// to get the maximum number of hex digits we can copy
// to get the maximum number of hex digits to copy
SQLLEN to_copy_hex = static_cast<SQLLEN>(floor(to_copy / (2 * extra)));
for( SQLLEN i = 0; i < to_copy_hex; ++i ) {
*h = hex_chars[(*b & 0xf0) >> 4];
@ -931,7 +932,7 @@ SQLRETURN binary_to_string( _Inout_ SQLCHAR* field_data, _Inout_ SQLLEN& read_so
h++;
}
read_so_far += to_copy_hex;
*h = static_cast<Char>( 0 );
*h = static_cast<Char>(0);
}
else {
reinterpret_cast<char*>( buffer )[0] = '\0';

49
source/shared/core_stream.cpp
View file

@ -101,13 +101,18 @@ size_t sqlsrv_stream_read(_Inout_ php_stream* stream, _Out_writes_bytes_(count)
throw core::CoreException();
}
// if the stream returns either no data, NULL data, or returns data < than the count requested then
// we are at the "end of the stream" so we mark it
if( r == SQL_NO_DATA || read == SQL_NULL_DATA || ( static_cast<size_t>( read ) <= count && read != SQL_NO_TOTAL )) {
// If the stream returns no data or NULL data, mark the "end of the stream" and return
if( r == SQL_NO_DATA || read == SQL_NULL_DATA) {
stream->eof = 1;
return 0;
}
// If the stream returns data less than the count requested then we are at the "end of the stream" but continue processing
if (static_cast<size_t>(read) <= count && read != SQL_NO_TOTAL) {
stream->eof = 1;
}
// if ODBC returns the 01004 (truncated string) warning, then we return the count minus the null terminator
// If ODBC returns the 01004 (truncated string) warning, then we return the count minus the null terminator
// if it's not a binary encoded field
if( r == SQL_SUCCESS_WITH_INFO ) {
@ -120,26 +125,42 @@ size_t sqlsrv_stream_read(_Inout_ php_stream* stream, _Out_writes_bytes_(count)
SQLSRV_ASSERT( is_truncated_warning( state ), "sqlsrv_stream_read: truncation warning was expected but it "
"did not occur." );
}
// with unixODBC connection pooling enabled the truncated state may not be returned so check the actual length read
// with buffer length.
// As per SQLGetData documentation, if the length of character data exceeds the BufferLength,
// SQLGetData truncates the data to BufferLength less the length of null-termination character.
// But when fetching binary fields as chars (wide chars), each byte is represented as 2 hex characters,
// each takes the size of a char (wide char). Note that BufferLength may not be multiples of 2 or 4.
bool is_binary = (ss->sql_type == SQL_BINARY || ss->sql_type == SQL_VARBINARY || ss->sql_type == SQL_LONGVARBINARY);
// With unixODBC connection pooling enabled the truncated state may not be returned so check the actual length read
// with buffer length.
#ifndef _WIN32
if( is_truncated_warning( state ) || count < read) {
#else
if( is_truncated_warning( state ) ) {
#endif // !_WIN32
size_t char_size = sizeof(SQLCHAR);
switch( c_type ) {
// As per SQLGetData documentation, if the length of character data exceeds the BufferLength,
// SQLGetData truncates the data to BufferLength less the length of null-termination character.
case SQL_C_BINARY:
read = count;
break;
case SQL_C_WCHAR:
read = ( count % 2 == 0 ? count - 2 : count - 3 );
char_size = sizeof(SQLWCHAR);
if (is_binary) {
// Each binary byte read will be 2 hex wide chars in the buffer
SQLLEN num_bytes_read = static_cast<SQLLEN>(floor((count - char_size) / (2 * char_size)));
read = num_bytes_read * char_size * 2 ;
} else {
read = (count % 2 == 0 ? count - 2 : count - 3);
}
break;
case SQL_C_CHAR:
read = count - 1;
if (is_binary) {
read = ((count - char_size) % 2 == 0 ? count - char_size : count - char_size - 1);
} else {
read = count - 1;
}
break;
default:
DIE( "sqlsrv_stream_read: should have never reached in this switch case.");
@ -151,10 +172,10 @@ size_t sqlsrv_stream_read(_Inout_ php_stream* stream, _Out_writes_bytes_(count)
}
}
// if the encoding is UTF-8
// If the encoding is UTF-8
if( c_type == SQL_C_WCHAR ) {
count *= 2;
// undo the shift to use the full buffer
// Undo the shift to use the full buffer
// flags set to 0 by default, which means that any invalid characters are dropped rather than causing
// an error. This happens only on XP.
// convert to UTF-8

41
test/functional/sqlsrv/sqlsrv_fetch_large_stream_binary.phpt
View file

@ -18,10 +18,23 @@ function fetchNull($stmt, $sqltype, $message)
}
}
function fetchNullStream($stmt, $sqltype, $message)
{
$stream = sqlsrv_get_field($stmt, 1, $sqltype);
if ($stream !== false) {
$value = fread($stream, 8192);
fclose($stream);
if (!empty($value)) {
echo("$message: expected an empty value\n");
}
}
}
function fetchStream($stmt, $test)
{
global $binaryValue, $hexValue;
if (!sqlsrv_execute($stmt)) {
fatalError("fetchStream: failed to execute select");
}
@ -32,17 +45,17 @@ function fetchStream($stmt, $test)
switch ($test) {
case 1:
$sqltype = SQLSRV_PHPTYPE_STREAM(SQLSRV_ENC_CHAR);
trace("fetchStream (char string):\n");
$type = 'char string';
$expected = $hexValue;
break;
case 2:
$sqltype = SQLSRV_PHPTYPE_STREAM('UTF-8');
trace("fetchStream (char string):\n");
$type = 'UTF-8 string';
$expected = $hexValue;
break;
case 3:
$sqltype = SQLSRV_PHPTYPE_STREAM(SQLSRV_ENC_BINARY);
trace("fetchStream (binary string):\n");
$type = 'binary string';
$expected = $binaryValue;
break;
default:
@ -50,6 +63,7 @@ function fetchStream($stmt, $test)
break;
}
trace("fetchStream ($type):\n");
$stream = sqlsrv_get_field($stmt, 0, $sqltype);
if ($stream !== false) {
$value = '';
@ -58,11 +72,13 @@ function fetchStream($stmt, $test)
}
fclose($stream);
if (!checkData($value, $expected)) {
echo("Expected:\n$expected\nActual:\n$value\n");
echo("fetchStream ($type)\nExpected:\n$expected\nActual:\n$value\n");
}
} else {
fatalError("fetchStream ($test) failed");
fatalError("fetchStream ($type) failed");
}
fetchNullStream($stmt, $sqltype, "fetchStream ($type)\n");
}
function fetchData($stmt, $test)
@ -79,17 +95,17 @@ function fetchData($stmt, $test)
switch ($test) {
case 1:
$sqltype = SQLSRV_PHPTYPE_STRING(SQLSRV_ENC_CHAR);
trace("fetchData (char string):\n");
$type = 'char string';
$expected = $hexValue;
break;
case 2:
$sqltype = SQLSRV_PHPTYPE_STRING('UTF-8');
trace("fetchData (char string):\n");
$type = 'UTF-8 string';
$expected = $hexValue;
break;
case 3:
$sqltype = SQLSRV_PHPTYPE_STRING(SQLSRV_ENC_BINARY);
trace("fetchData (binary string):\n");
$type = 'binary string';
$expected = $binaryValue;
break;
default:
@ -97,12 +113,13 @@ function fetchData($stmt, $test)
break;
}
trace("fetchData ($type):\n");
$value = sqlsrv_get_field($stmt, 0, $sqltype);
if (!checkData($value, $expected)) {
echo("Expected:\n$expected\nActual:\n$value\n");
echo("fetchData ($type)\nExpected:\n$expected\nActual:\n$value\n");
}
fetchNull($stmt, $sqltype, "fetchData ($test)\n");
fetchNull($stmt, $sqltype, "fetchData ($type)\n");
}
function runTest($conn, $buffered)
@ -154,7 +171,7 @@ $columns = array(new AE\ColumnMeta("varbinary(max)", "varbinary_max_col"),
AE\createTable($conn, $tableName, $columns);
$bin = 'abcdefghijk';
$binaryValue = str_repeat($bin, 40);
$binaryValue = str_repeat($bin, 400);
$hexValue = strtoupper(bin2hex($binaryValue));
$insertSql = "INSERT INTO $tableName (varbinary_max_col, varbinary_null_col) VALUES (?, ?)";