/// <summary>
/// Creates a new instance of <see cref="Branch"/> (but does
/// not load it).
/// </summary>
/// <param name="store">The command store that this branch is part of (not null)</param>
/// <param name="ac">Metadata relating to the branch (not null)</param>
/// <exception cref="ArgumentNullException">
/// The supplied command store or metadata is undefined</exception>
internal Branch(CmdStore store, BranchInfo ac)
{
Store = store ?? throw new ArgumentNullException(nameof(store));
Info = ac ?? throw new ArgumentNullException(nameof(ac));
Commands = new List <CmdData>();
Parent = null;
Children = new List <Branch>();
}
/// <summary>
/// Performs the data processing associated with a command.
/// </summary>
public void Process(ExecutionContext context)
{
CmdStore cs = context?.Store ?? throw new ApplicationException("Undefined store");
uint numCmd = (Input as ICreateBranch).CommandCount;
if (numCmd == 0)
{
throw new ApplicationException(nameof(numCmd));
}
// Confirm that the name for the new branch is not a
// duplicate (considering just the children of the
// current branch)
string name = (Input as ICreateBranch).Name;
Branch parent = cs.Current;
Branch oldBranch = parent.GetChild(name);
if (oldBranch != null)
{
throw new ArgumentException(
$"Branch {name} previously created at {oldBranch.Info.CreatedAt}");
}
// Confirm that the new branch name is acceptable to the command store
if (!cs.IsValidBranchName(name))
{
throw new ArgumentException($"Branch name '{name}' is not allowed");
}
var ac = new BranchInfo(
storeId: cs.Id,
parentId: parent.Id,
branchId: Guid.NewGuid(),
branchName: name,
createdAt: Input.CreatedAt,
updatedAt: Input.CreatedAt,
commandDiscount: 1,
refreshCount: numCmd);
// Update internal structure to include the new branch
var newBranch = new Branch(cs, ac)
{
Parent = parent
};
parent.Children.Add(newBranch);
cs.Branches.Add(ac.BranchId, newBranch);
// Save the metadata for the new branch
cs.SaveBranchInfo(newBranch);
// And save the CreateBranch command itself
newBranch.SaveData(Input);
}
/// <summary>
/// Performs the data processing associated with a command.
/// </summary>
/// <remarks>If a call to this method completes without any exception,
/// a reference to the new store can be obtained using the
/// <see cref="ExecutionContext.Store"/> property.
/// </remarks>
public void Process(ExecutionContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
// Create the physical manifestation (if any) for the new store
var store = CmdStore.CreateStore(Input);
// Write the command data
store.Current.SaveData(Input);
context.Store = store;
}
public void Process(ExecutionContext context)
{
CmdStore cs = context.Store;
StoreInfo storeInfo = cs.Store;
string upLoc = storeInfo.UpstreamLocation;
if (String.IsNullOrEmpty(upLoc))
{
throw new ApplicationException("There is no upstream location");
}
// Collate the number of commands we have in local branches
IdCount[] have = cs.Branches.Values
.Where(x => !x.IsRemote)
.Select(x => new IdCount(x.Id, x.Info.CommandCount))
.ToArray();
IRemoteStore rs = context.GetRemoteStore(upLoc);
// We don't care about new branches in the origin, but we do care
// about local branches that have been created since the last push
IdRange[] toPush = rs.GetMissingRanges(cs.Id, have, false).ToArray();
// How many commands do we need to push
uint total = (uint)toPush.Sum(x => x.Size);
Log.Info($"To push {total} command`s in {toPush.Length} branch`es".TrimExtras());
foreach (IdRange idr in toPush)
{
Branch b = cs.FindBranch(idr.Id);
if (b == null)
{
throw new ApplicationException("Cannot locate branch " + idr.Id);
}
Log.Info($"Push [{idr.Min},{idr.Max}] from {b}");
CmdData[] data = b.TakeRange(idr.Min, idr.Max).ToArray();
rs.Push(cs.Name, b.Info, data);
// Remember how much we were ahead at the time of the push
b.Info.LastPush = idr.Max + 1;
b.Store.SaveBranchInfo(b);
}
Log.Info("Push completed");
}
public void Process(ExecutionContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
// Create the new store
var store = CmdStore.CreateStore(Input);
// Write the command data
// TODO: Does it need to be written anywhere? Perhaps to root metadata?
// We shouldn't really touch any of the branches that have just been copied.
//store.Current.SaveData(Input);
context.Store = store;
}
/// <summary>
/// Initializes a new instance of the <see cref="ExecutionContext"/> class.
/// </summary>
/// <param name="store">The command store (not null).</param>
/// <exception cref="ArgumentNullException">
/// The specified store is undefined.</exception>
public ExecutionContext(CmdStore store)
: this()
{
Store = store ?? throw new ArgumentNullException();
}
public void Process(ExecutionContext context)
{
CmdStore cs = context.Store;
StoreInfo storeInfo = cs.Store;
string upLoc = storeInfo.UpstreamLocation;
if (String.IsNullOrEmpty(upLoc))
{
throw new ApplicationException("There is no upstream location");
}
// Collate how much we already have in all remote branches.
// We may have previously pushed some local branches to the remote
// store, but nothing is supposed to mutate those remote copies.
IdCount[] have = cs.Branches.Values
.Where(x => x.IsRemote)
.Select(x => new IdCount(x.Id, x.Info.CommandCount))
.ToArray();
// Open a channel to the upstream store
IRemoteStore rs = context.GetRemoteStore(upLoc);
// Determine what we are missing (including any new branches in the remote)
IdRange[] toFetch = rs.GetMissingRanges(cs.Id, have, true);
// How many commands do we need to fetch
uint total = (uint)toFetch.Sum(x => x.Size);
Log.Info($"To fetch {total} command`s from {toFetch.Length} branch`es".TrimExtras());
// Retrieve the command data from the remote, keeping new branches
// apart from appends to existing branches.
var newBranchData = new Dictionary <BranchInfo, CmdData[]>();
var moreBranchData = new Dictionary <BranchInfo, CmdData[]>();
foreach (IdRange idr in toFetch)
{
// Fetch the remote AC file
BranchInfo ac = rs.GetBranchInfo(idr.Id);
if (ac == null)
{
throw new ApplicationException("Could not locate remote branch " + idr.Id);
}
// And the relevant data
Log.Info($"Fetch [{idr.Min},{idr.Max}] for {ac.BranchName} ({ac.BranchId})");
CmdData[] branchData = rs.GetData(idr).ToArray();
if (cs.FindBranch(ac.BranchId) == null)
{
newBranchData.Add(ac, branchData);
}
else
{
moreBranchData.Add(ac, branchData);
}
}
// All done with the remote store
// Copy any brand new branches (ensuring they get created in the
// right order so that parent/child relationships can be formed
// as we go).
foreach (KeyValuePair <BranchInfo, CmdData[]> kvp in newBranchData.OrderBy(x => x.Key.CreatedAt))
{
cs.CopyIn(kvp.Key, kvp.Value);
}
// Append command data for branches we previously had (the order
// shouldn't matter)
foreach (KeyValuePair <BranchInfo, CmdData[]> kvp in moreBranchData)
{
cs.CopyIn(kvp.Key, kvp.Value);
}
Log.Info("Fetch completed");
// Reload the current command stream (from scratch, kind of brute force,
// not sure whether appending the new commands would really be sufficient)
// TODO: Is this really necessary? Perhaps only if the current branch has
// been fetched (the stuff we're fetching should only come from remotes,
// but the current branch could be one of those remotes)
//cs.Stream = new CmdStream(cs.Current);
}
public void Process(ExecutionContext context)
{
Guid sourceId = (Input as IMerge).FromId;
CmdStore cs = context.Store;
Branch target = cs.Current;
Branch source = cs.FindBranch(sourceId);
if (source == null)
{
throw new ApplicationException($"Cannot locate branch {sourceId}");
}
// Merges can only be done between branches that are part
// of the local store (fetches from remote stores should
// involve a totally different set of branches)
//if (target.Info.StoreId != source.Info.StoreId)
// throw new NotSupportedException("Attempt to merge with a remote store");
// Determine the first command that needs to be merged from
// the source branch. The source branch doesn't know anything
// about merges that have already been done, so figuring this
// out involves scanning back from the end of the target branch
// to locate the last merge (if any).
// How far we go back depends on whether we're merging from
// a child branch to its parent, or vice versa. If the target
// is the child we go back as far as command 0. If the target
// is the parent, we go back as far the command that followed
// the branch start point.
bool targetIsParent = target.Id.Equals(source.Info.ParentId);
// Define the range of commands to be merged from the source
uint minCmd = 0;
if (targetIsParent)
{
// Merging into the parent, so start from the command immediately
// after the last command that was previously merged (or 0 if this
// is the first time the parent has merged from the child).
if (target.Info.LastMerge.TryGetValue(sourceId, out MergeInfo mi))
{
minCmd = mi.ChildCount;
}
}
else
{
// Merging from the parent into the child, so start from the command
// immediately after the last command that was previously merged (it
// could potentially be 0)
minCmd = target.Info.RefreshCount;
}
uint maxCmd = (uint)source.Info.CommandCount - 1;
// TODO: Round about here we need to actually include the new stuff
// as part of the current stream. Replaying the commands may then
// lead to some sort of conflict (things are not guaranteed to work),
// so there needs to be some way to preview the results.
// Write the command data
Input.Add(nameof(IMerge.MinCmd), minCmd);
Input.Add(nameof(IMerge.MaxCmd), maxCmd);
target.SaveData(Input);
}