Change IBackend.List() to return IEnumerable instead of List

By changing to IEnumerable, it is possible to iterate only a portion of the list, which is useful when not all entries are needed (e.g., when testing a connection).
All existing backends have been updated, and any which were able to be changed to yield return results in a straightforward way now do.
Many backends had a try/catch in the List() method. Due to the fact that yield returns can't be placed within a try/catch block, these have been refactored to either scope the try/catch to the parts that (should) be the only places throwing exceptions, so that exceptions are still caught and handled.
Note that lazy evaluation may cause some changes in behavior - exceptions that were previously thrown at the point of invokation of List() may now be thrown while it is being enumerated.
I believe this will not be problematic though, as the only well-known exception seems to be FolderMissingException, which should be thrown by Test(), but TestList() attempts to enumerate the list to force this exception.
Any places that require the legacy behavior can get it by simply converting the lazy enumerable to a List()

1 files changed, 1 insertions, 1 deletions

diff --git a/Duplicati/Library/Backend/HubiC/HubiCBackend.cs b/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
index 748842d59..1f8fb03c0 100644
--- a/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
+++ b/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
@@ -21,6 +21,6 @@ namespace Duplicati.Library.Backend.HubiC
     public class HubiCBackend : IBackend, IStreamingBackend

     {
        private const string AUTHID_OPTION = "authid";
        private const string HUBIC_API_URL = "https://api.hubic.com/1.0/";
        private const string HUBIC_API_CREDENTIAL_URL = HUBIC_API_URL + "account/credentials";

        private OpenStackStorage m_openstack;

        private class HubiCAuthResponse
        {
            public string token { get; set; }
            public string endpoint { get; set; }
            public DateTime? expires { get; set;}
        }

        private class OpenStackHelper : OpenStackStorage
        {
            private OAuthHelper m_helper;
            private HubiCAuthResponse m_token;

            public OpenStackHelper(string authid, string url)
                : base(url, MockOptions())
            {
                m_helper = new OAuthHelper(authid, "hubic") { AutoAuthHeader = true };
            }

            private static Dictionary<string, string> MockOptions()
            {
                var res = new Dictionary<string, string>();
                res["openstack-authuri"] = "invalid://dont-use";
                res["openstack-apikey"] = "invalid";
                res["auth-username"] = "invalid";

                return res;
            }

            private HubiCAuthResponse AuthToken
            {
                get
                {
                    if (m_token == null || (m_token.expires != null && (m_token.expires.Value - DateTime.UtcNow).TotalSeconds < 30))
                        m_token = m_helper.ReadJSONResponse<HubiCAuthResponse>(HUBIC_API_CREDENTIAL_URL);
                    return m_token;
                }
            }

            protected override string AccessToken
            {
                get { return AuthToken.token; }
            }

            protected override string SimpleStorageEndPoint
            {
                get { return AuthToken.endpoint; }
            }
        }

        public HubiCBackend()

         {
        }

-
        public HubiCBackend(string url, Dictionary<string, string> options)
        {
            string authid = null;
            if (options.ContainsKey(AUTHID_OPTION))
                authid = options[AUTHID_OPTION];

            m_openstack = new OpenStackHelper(authid, url);
        }

        #region IStreamingBackend implementation

        public void Put(string remotename, System.IO.Stream stream)
        {
            m_openstack.Put(remotename, stream);
        }

        public void Get(string remotename, System.IO.Stream stream)
        {
            m_openstack.Get(remotename, stream);
        }

        #endregion

        #region IBackend implementation

        public List<IFileEntry> List()
        {
            return m_openstack.List();
        }

        public void Put(string remotename, string filename)
        {
            m_openstack.Put(remotename, filename);
        }

        public void Get(string remotename, string filename)
        {
            m_openstack.Get(remotename, filename);
        }

        public void Delete(string remotename)
        {
            m_openstack.Delete(remotename);
        }

        public void Test()
        {
            m_openstack.Test();
        }

        public void CreateFolder()
        {
            m_openstack.CreateFolder();
        }

        public string DisplayName
        {
            get
            {
                return Strings.HubiC.DisplayName;
            }
        }

        public string ProtocolKey
        {
            get
            {
                return "hubic";
            }
        }

        public System.Collections.Generic.IList<ICommandLineArgument> SupportedCommands
        {
            get {
                return new List<ICommandLineArgument>(new ICommandLineArgument[] {
                    new CommandLineArgument(AUTHID_OPTION, CommandLineArgument.ArgumentType.Password, Strings.HubiC.AuthidShort, Strings.HubiC.AuthidLong(OAuthHelper.OAUTH_LOGIN_URL("hubic"))),
                });
            }
        }

        public string Description
        {
            get
            {
                return Strings.HubiC.Description;
            }
        }

        #endregion

        #region IDisposable implementation

        public void Dispose()
        {
            if (m_openstack != null)
            {
                m_openstack.Dispose();
                m_openstack = null;
            }
        }

        #endregion
    }

+
        public HubiCBackend(string url, Dictionary<string, string> options)
        {
            string authid = null;
            if (options.ContainsKey(AUTHID_OPTION))
                authid = options[AUTHID_OPTION];

            m_openstack = new OpenStackHelper(authid, url);
        }

        #region IStreamingBackend implementation

        public void Put(string remotename, System.IO.Stream stream)
        {
            m_openstack.Put(remotename, stream);
        }

        public void Get(string remotename, System.IO.Stream stream)
        {
            m_openstack.Get(remotename, stream);
        }

        #endregion

        #region IBackend implementation

        public IEnumerable<IFileEntry> List()
        {
            return m_openstack.List();
        }

        public void Put(string remotename, string filename)
        {
            m_openstack.Put(remotename, filename);
        }

        public void Get(string remotename, string filename)
        {
            m_openstack.Get(remotename, filename);
        }

        public void Delete(string remotename)
        {
            m_openstack.Delete(remotename);
        }

        public void Test()
        {
            m_openstack.Test();
        }

        public void CreateFolder()
        {
            m_openstack.CreateFolder();
        }

        public string DisplayName
        {
            get
            {
                return Strings.HubiC.DisplayName;
            }
        }

        public string ProtocolKey
        {
            get
            {
                return "hubic";
            }
        }

        public System.Collections.Generic.IList<ICommandLineArgument> SupportedCommands
        {
            get {
                return new List<ICommandLineArgument>(new ICommandLineArgument[] {
                    new CommandLineArgument(AUTHID_OPTION, CommandLineArgument.ArgumentType.Password, Strings.HubiC.AuthidShort, Strings.HubiC.AuthidLong(OAuthHelper.OAUTH_LOGIN_URL("hubic"))),
                });
            }
        }

        public string Description
        {
            get
            {
                return Strings.HubiC.Description;
            }
        }

        #endregion

        #region IDisposable implementation

        public void Dispose()
        {
            if (m_openstack != null)
            {
                m_openstack.Dispose();
                m_openstack = null;
            }
        }

        #endregion
    }

 }