public static Errorable<Tag.Builder> FromJSON(this TagRequest tgm)
{
// Do conversions on the strings and detect any errors:
var maybecommitid = CommitID.TryParse(tgm.commitid ?? String.Empty);
if (maybecommitid.HasErrors) return maybecommitid.Errors;
Tag.Builder tg = new Tag.Builder(
pName: (TagName)tgm.name,
pCommitID: maybecommitid.Value,
pTagger: tgm.tagger ?? String.Empty,
pDateTagged: String.IsNullOrWhiteSpace(tgm.date_tagged) ? DateTimeOffset.Now : ToDate(tgm.date_tagged),
pMessage: tgm.message ?? String.Empty
);
return tg;
}
private async Task<Errorable<Tag>> getTag(TagID id)
{
FileInfo fi = system.getPathByID(id);
if (!fi.Exists) return new TagIDRecordDoesNotExistError(id);
byte[] buf;
int nr = 0;
using (var fs = new FileStream(fi.FullName, FileMode.Open, FileAccess.Read, FileShare.Read, 16384, true))
{
// TODO: implement an async buffered Stream:
buf = new byte[16384];
nr = await fs.ReadAsync(buf, 0, 16384).ConfigureAwait(continueOnCapturedContext: false);
if (nr >= 16384)
{
// My, what a large tag you have!
throw new NotSupportedException();
}
}
Tag.Builder tb = new Tag.Builder();
// Parse the Tag:
using (var ms = new MemoryStream(buf, 0, nr, false))
using (var sr = new StreamReader(ms, Encoding.UTF8))
{
string line = sr.ReadLine();
// Set CommitID:
if (line == null || !line.StartsWith("commit ")) return new TagParseExpectedCommitError();
var ecid = CommitID.TryParse(line.Substring("commit ".Length));
if (ecid.HasErrors) return ecid.Errors;
tb.CommitID = ecid.Value;
// Set Name:
line = sr.ReadLine();
if (line == null || !line.StartsWith("name ")) return new TagParseExpectedNameError();
tb.Name = (TagName)line.Substring("name ".Length);
// Set Tagger:
line = sr.ReadLine();
if (line == null || !line.StartsWith("tagger ")) return new TagParseExpectedTaggerError();
tb.Tagger = line.Substring("tagger ".Length);
// Set DateTagged:
line = sr.ReadLine();
if (line == null || !line.StartsWith("date ")) return new TagParseExpectedDateError();
// NOTE: date parsing will result in an inexact DateTimeOffset from what was created with, but it
// is close enough because the SHA-1 hash is calculated using the DateTimeOffset.ToString(), so
// only the ToString() representations of the DateTimeOffsets need to match.
DateTimeOffset tmpDate;
if (!DateTimeOffset.TryParse(line.Substring("date ".Length), out tmpDate))
return new TagParseBadDateFormatError();
tb.DateTagged = tmpDate;
// Skip empty line:
line = sr.ReadLine();
if (line == null || line.Length != 0) return new TagParseExpectedBlankLineError();
// Set Message:
tb.Message = sr.ReadToEnd();
}
// Create the immutable Tag from the Builder:
Tag tg = tb;
// Validate the computed TagID:
if (tg.ID != id) return new ComputedTagIDMismatchError(tg.ID, id);
return tg;
}
