/// <summary>
/// Retrieves a hash for the given file, either cached from this file content table or by hashing the file.
/// If the file must be hashed (cache miss), the computed hash is stored in the file content table.
/// </summary>
/// <exception cref="BuildXLException">Thrown if accessing the local path specified by 'key' fails.</exception>
public static async Task <VersionedFileIdentityAndContentInfoWithOrigin> GetAndRecordContentHashAsync(
this FileContentTable fileContentTable,
FileStream contentStream,
bool?strict = default,
bool ignoreKnownContentHash = false)
{
Contract.Requires(fileContentTable != null);
Contract.Requires(contentStream != null);
if (!ignoreKnownContentHash)
{
VersionedFileIdentityAndContentInfo?existingInfo = fileContentTable.TryGetKnownContentHash(contentStream);
if (existingInfo.HasValue)
{
return(new VersionedFileIdentityAndContentInfoWithOrigin(existingInfo.Value, ContentHashOrigin.Cached));
}
}
ContentHash newHash = await ContentHashingUtilities.HashContentStreamAsync(contentStream);
VersionedFileIdentityAndContentInfo newInfo = fileContentTable.RecordContentHash(
contentStream,
newHash,
strict: strict);
return(new VersionedFileIdentityAndContentInfoWithOrigin(newInfo, ContentHashOrigin.NewlyHashed));
}
