public void FieldOffsetsAreAutoAssigned(DbaseField[] fields, ByteOffset[] expected)
{
var sut = new AnonymousDbaseSchema(fields);
Assert.Equal(
sut.Fields.Select(field => field.Offset).ToArray(),
expected);
}
public void ConstructionUsingFieldsHasExpectedResult()
{
var fields = _fixture.GenerateDbaseFields();
var length = fields.Aggregate(DbaseRecordLength.Initial, (current, field) => current.Plus(field.Length));
var sut = new AnonymousDbaseSchema(fields);
Assert.Equal(fields, sut.Fields);
Assert.Equal(length, sut.Length);
}
public static DbaseFileHeader Read(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
if (reader.ReadByte() != ExpectedDbaseFormat)
{
throw new DbaseFileHeaderException("The database file type must be 3 (dBase III).");
}
var lastUpdated = new DateTime(reader.ReadByte() + 1900, reader.ReadByte(), reader.ReadByte(), 0, 0, 0,
DateTimeKind.Unspecified);
var recordCount = new DbaseRecordCount(reader.ReadInt32());
var headerLength = reader.ReadInt16();
var fieldCount = (headerLength - HeaderMetaDataSize) / FieldMetaDataSize;
if (fieldCount > DbaseSchema.MaximumFieldCount)
{
throw new DbaseFileHeaderException(
$"The database file can not contain more than {DbaseSchema.MaximumFieldCount} fields.");
}
var recordLength = new DbaseRecordLength(reader.ReadInt16());
reader.ReadBytes(17);
var rawCodePage = reader.ReadByte();
if (!DbaseCodePage.TryParse(rawCodePage, out var codePage))
{
throw new DbaseFileHeaderException($"The database code page {rawCodePage} is not supported.");
}
reader.ReadBytes(2);
var fields = new DbaseField[fieldCount];
for (var recordFieldIndex = 0; recordFieldIndex < fieldCount; recordFieldIndex++)
{
fields[recordFieldIndex] = DbaseField.Read(reader);
}
// verify field offsets are aligned
var offset = ByteOffset.Initial;
foreach (var field in fields)
{
if (field.Offset != offset)
{
throw new DbaseFileHeaderException(
$"The field {field.Name} does not have the expected offset {offset} but instead {field.Offset}. Please ensure the offset has been properly set for each field and that the order in which they appear in the record field layout matches their offset.");
}
offset = field.Offset.Plus(field.Length);
}
var schema = new AnonymousDbaseSchema(fields);
if (recordLength != schema.Length)
{
throw new DbaseFileHeaderException(
$"The database file record length ({recordLength}) does not match the total length of all fields ({schema.Length}).");
}
if (reader.ReadByte() != Terminator)
{
throw new DbaseFileHeaderException("The database file header terminator is missing.");
}
// skip to first record
var bytesToSkip = headerLength - (HeaderMetaDataSize + FieldMetaDataSize * fieldCount);
reader.ReadBytes(bytesToSkip);
return(new DbaseFileHeader(lastUpdated, codePage, recordCount, schema));
}