/// <summary>
/// A factory method attempting to create an instance of entry out of array of fields as extracted from
/// a single line in Storage Analytics Log file.
/// </summary>
/// <param name="fields">
/// Array of string values of fields as extracted from a single line in a log file.
/// It must not be null and should contain exactly 30 items.
/// </param>
/// <returns>A valid instance of <see cref="StorageAnalyticsLogEntry"/> if given fields match expected format,
/// or null otherwise.</returns>
public static StorageAnalyticsLogEntry TryParse(string[] fields)
{
Debug.Assert(fields != null);
Debug.Assert(fields.Length == (int)StorageAnalyticsLogColumnId.LastColumn + 1);
var entry = new StorageAnalyticsLogEntry();
DateTime requestStartTime;
if (!DateTime.TryParseExact(fields[(int)StorageAnalyticsLogColumnId.RequestStartTime], "o",
CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out requestStartTime))
{
return(null);
}
entry.RequestStartTime = requestStartTime;
StorageServiceType serviceType;
if (Enum.TryParse <StorageServiceType>(fields[(int)StorageAnalyticsLogColumnId.ServiceType], true,
out serviceType))
{
entry.ServiceType = serviceType;
StorageServiceOperationType operationType;
if (Enum.TryParse <StorageServiceOperationType>(fields[(int)StorageAnalyticsLogColumnId.OperationType],
out operationType))
{
entry.OperationType = operationType;
}
entry.RequestedObjectKey = fields[(int)StorageAnalyticsLogColumnId.RequestedObjectKey];
}
return(entry);
}
/// <summary>
/// Given a log file (as a blob), parses it and return a collection of log entries matching version 1.0
/// of the Storage Analytics Log Format.
/// </summary>
/// <param name="blob">Object representing a cloud blob with Storage Analytics log content.</param>
/// <param name="cancellationToken">A token to monitor for cancellation request.</param>
/// <returns>Collection of successfully parsed log entries.</returns>
/// <exception cref="FormatException">If unable to parse a line in given log.</exception>
/// <seealso cref="StorageAnalyticsLogEntry"/>
/// <remarks>
/// The method scans log file lines one at a time.
/// First it attempts to detect a line format version and throws an exception if failed to do so.
/// It skips all lines with version different than supported one, i.e. 1.0.
/// Then it calls TryParseLogEntry to create a log entry out of every line of supported version and throws
/// an exception if the parse method returns null.
/// </remarks>
public async Task <IEnumerable <StorageAnalyticsLogEntry> > ParseLogAsync(BlobBaseClient blob,
CancellationToken cancellationToken)
{
List <StorageAnalyticsLogEntry> entries = new List <StorageAnalyticsLogEntry>();
using (Stream content = (await blob.DownloadAsync(cancellationToken).ConfigureAwait(false)).Value.Content)
{
using (TextReader tr = new StreamReader(content))
{
for (int lineNumber = 1; ; lineNumber++)
{
cancellationToken.ThrowIfCancellationRequested();
string line = await tr.ReadLineAsync().ConfigureAwait(false);
if (line == null)
{
break;
}
Version version = TryParseVersion(line);
if (version == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to detect a version of log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
_logger.LogWarning(message);
}
if (version == supportedVersion)
{
StorageAnalyticsLogEntry entry = TryParseLogEntry(line);
if (entry == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to parse the log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
_logger.LogWarning(message);
}
entries.Add(entry);
}
}
}
}
return(entries);
}
/// <summary>
/// Attempts to parse a single line of Storage Analytics Log file using Regex matches.
/// </summary>
/// <param name="line">A line as extracted from a Storage Analytics Log file. Must not be null or empty.</param>
/// <returns>Parsed instance of <see cref="StorageAnalyticsLogEntry"/> if the given line matches expected format
/// of the Storage Analytics Log v1.0, or null otherwise.</returns>
public StorageAnalyticsLogEntry TryParseLogEntry(string line)
{
Debug.Assert(line != null);
var capturedFields =
from Match m in _compiledRegex.Matches(line)
select WebUtility.HtmlDecode(m.Groups[1].Value);
string[] fieldsArray = capturedFields.ToArray();
if (fieldsArray.Length != ColumnCount)
{
return(null);
}
return(StorageAnalyticsLogEntry.TryParse(fieldsArray));
}
/// <summary>
/// Given a log file (as a blob), parses it and return a collection of log entries matching version 1.0
/// of the Storage Analytics Log Format.
/// </summary>
/// <param name="blob">Object representing a cloud blob with Storage Analytics log content.</param>
/// <param name="cancellationToken">A token to monitor for cancellation request.</param>
/// <returns>Collection of successfully parsed log entries.</returns>
/// <exception cref="FormatException">If unable to parse a line in given log.</exception>
/// <seealso cref="StorageAnalyticsLogEntry"/>
/// <remarks>
/// The method scans log file lines one at a time.
/// First it attempts to detect a line format version and throws an exception if failed to do so.
/// It skips all lines with version different than supported one, i.e. 1.0.
/// Then it calls TryParseLogEntry to create a log entry out of every line of supported version and throws
/// an exception if the parse method returns null.
/// </remarks>
public async Task <IEnumerable <StorageAnalyticsLogEntry> > ParseLogAsync(ICloudBlob blob,
CancellationToken cancellationToken)
{
List <StorageAnalyticsLogEntry> entries = new List <StorageAnalyticsLogEntry>();
using (TextReader tr = new StreamReader(await blob.OpenReadAsync(cancellationToken)))
{
for (int lineNumber = 1; ; lineNumber++)
{
cancellationToken.ThrowIfCancellationRequested();
string line = await tr.ReadLineAsync();
if (line == null)
{
break;
}
Version version = TryParseVersion(line);
if (version == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to detect a version of log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
if (version == supportedVersion)
{
StorageAnalyticsLogEntry entry = TryParseLogEntry(line);
if (entry == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to parse the log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
entries.Add(entry);
}
}
}
return(entries);
}
private static StorageAnalyticsLogEntry CreateEntry(string requestStartTime, StorageServiceOperationType operationType, StorageServiceType serviceType, string requestedObjectKey)
{
StorageAnalyticsLogEntry entry = new StorageAnalyticsLogEntry();
entry.RequestStartTime = DateTime.Parse(requestStartTime, CultureInfo.InvariantCulture);
entry.OperationType = operationType;
entry.ServiceType = serviceType;
entry.RequestedObjectKey = requestedObjectKey;
return entry;
}
/// <summary>
/// A factory method attempting to create an instance of entry out of array of fields as extracted from
/// a single line in Storage Analytics Log file.
/// </summary>
/// <param name="fields">
/// Array of string values of fields as extracted from a single line in a log file.
/// It must not be null and should contain exactly 30 items.
/// </param>
/// <returns>A valid instance of <see cref="StorageAnalyticsLogEntry"/> if given fields match expected format,
/// or null otherwise.</returns>
public static StorageAnalyticsLogEntry TryParse(string[] fields)
{
Debug.Assert(fields != null);
Debug.Assert(fields.Length == (int)StorageAnalyticsLogColumnId.LastColumn + 1);
var entry = new StorageAnalyticsLogEntry();
DateTime requestStartTime;
if (!DateTime.TryParseExact(fields[(int)StorageAnalyticsLogColumnId.RequestStartTime], "o",
CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out requestStartTime))
{
return null;
}
entry.RequestStartTime = requestStartTime;
StorageServiceType serviceType;
if (Enum.TryParse<StorageServiceType>(fields[(int)StorageAnalyticsLogColumnId.ServiceType], true,
out serviceType))
{
entry.ServiceType = serviceType;
StorageServiceOperationType operationType;
if (Enum.TryParse<StorageServiceOperationType>(fields[(int)StorageAnalyticsLogColumnId.OperationType],
out operationType))
{
entry.OperationType = operationType;
}
entry.RequestedObjectKey = fields[(int)StorageAnalyticsLogColumnId.RequestedObjectKey];
}
return entry;
}
