private static (ICollection <IPlcItem> ValidItems, ICollection <(IPlcItem FailedItem, string ErrorMessage)>) VerifyPlcItemResults(ICollection <ReadPlcItemWrapper> mapping, ICollection <AGL4.DATA_RW40> allAgLinkItems, bool transferData)
{
var validItems = new List <IPlcItem>(mapping.Count);
var failedItems = new List <(IPlcItem FailedItem, string ErrorMessage)>(0); //! Assume that no errors occur to save memory.
// Iterate each plc item and get the data for all AGLink items that where needed to handle it.
foreach (var(plcItem, start, amount) in mapping)
{
// Get all ag link items of this plc item.
var agLinkItems = allAgLinkItems.Skip(start).Take(amount).ToArray();
// Check if any of those have failed.
var itemResult = agLinkItems
.Select(agLinkItem => agLinkItem.Result)
.FirstOrDefault(resultCode => resultCode != 0)
;
var result = AgLinkPlc.ConvertToAgLinkResult(itemResult);
if (result != AgLinkResult.Success)
{
failedItems.Add((plcItem, AgLinkPlc.ErrorMapping.GetErrorMessageForCode(itemResult)));
}
else
{
validItems.Add(plcItem);
if (transferData)
{
var data = agLinkItems.SelectMany(agLinkItem => agLinkItem.B).ToArray();
AgLinkPlc.TransferValue(plcItem, data);
}
}
}
return(validItems, failedItems);
}
private static (ICollection <ReadPlcItemWrapper> Mapping, AGL4.DATA_RW40[] AllAgLinkItems) CreateMappingAndAgLinkItems(ICollection <IPlcItem> plcItems, PlcItemUsageType usageType)
{
var mapping = plcItems
.Select(plcItem => new ReadPlcItemWrapper(plcItem))
.ToArray()
;
// Create all needed AGLink items.
//! Directly storing the AGLink items in the ReadPlcItemWrapper instance won't work, as AGL4.DATA_RW40 is a struct that would consequently be copied on assignment.
//! Therefore the ReadPlcItemWrapper only contains the start position and the amount of items in the returned AGLink items array.
var previousAmount = 0;
var allAgLinkItems = mapping
.SelectMany
(
readPlcItemWrapper =>
{
var agLinkItems = AgLinkPlc.CreateAgLinkItems(readPlcItemWrapper.PlcItem, usageType).ToArray();
readPlcItemWrapper.Start = (previousAmount += agLinkItems.Length) - 1;
readPlcItemWrapper.Amount = agLinkItems.Length;
return(agLinkItems);
}
)
.ToArray()
;
return(mapping, allAgLinkItems);
}
private async Task PerformWriteAsync(ICollection <IPlcItem> plcItems, CancellationToken cancellationToken)
{
const PlcItemUsageType usageType = PlcItemUsageType.Write;
var underlyingPlc = AgLinkPlc.VerifyConnectivity(this, plcItems, usageType);
// Create the mapping.
var(mapping, allAgLinkItems) = AgLinkPlc.CreateMappingAndAgLinkItems(plcItems, usageType);
// Write to the plc.
var writeResult = await Task.Run(() => underlyingPlc.WriteMixEx(allAgLinkItems, allAgLinkItems.Length), cancellationToken);
// Verify the total result.
//! Ignore the total result and inspect the result of each item individually.
var result = AgLinkPlc.ConvertToAgLinkResult(writeResult);
//if (result != AgLinkResult.Success)
//{
// var errorMessage = AgLinkPlc.ErrorMapping.GetErrorMessageForCode(writeResult);
// var items = plcItems.Select(item => (item, "General writing error.")).ToArray();
// throw new WritePlcException(new IPlcItem[0], items, $"Could not write any items to {this:LOG}. AGLink returned error code '{result}' ({errorMessage}).");
//}
// Verify the result of all items.
var(validItems, failedItems) = AgLinkPlc.VerifyPlcItemResults(mapping, allAgLinkItems, false);
if (failedItems.Any())
{
throw new WritePlcException(validItems, failedItems, $"Some of the items couldn't be written. See the '{nameof(ReadOrWritePlcException.FailedItems)}' property for further information.");
}
}
private async Task PerformReadAsync(ICollection <IPlcItem> plcItems, CancellationToken cancellationToken)
{
const PlcItemUsageType usageType = PlcItemUsageType.Read;
var underlyingPlc = AgLinkPlc.VerifyConnectivity(this, plcItems, usageType);
// Create the mapping.
var(mapping, allAgLinkItems) = AgLinkPlc.CreateMappingAndAgLinkItems(plcItems, usageType);
// Read from the plc.
//! The return value may be zero even if some or all of the items failed. To get the real result the 'Result' property of the AGLink item (AGL4.DATA_RW40.Result) must be checked.
var readResult = await Task.Run(() => underlyingPlc.ReadMixEx(allAgLinkItems, allAgLinkItems.Length), cancellationToken);
// Verify the total result.
//! Ignore the total result and inspect the result of each item individually.
var result = AgLinkPlc.ConvertToAgLinkResult(readResult);
//if (result != AgLinkResult.Success)
//{
// var errorMessage = AgLinkPlc.ErrorMapping.GetErrorMessageForCode(readResult);
// var items = plcItems.Select(item => (item, "General reading error.")).ToArray();
// throw new ReadPlcException(new IPlcItem[0], items, $"Could not read any items from {this:LOG}. AGLink returned error code '{result}' ({errorMessage}).");
//}
// Verify the result of all items and transfer the value.
var(validItems, failedItems) = AgLinkPlc.VerifyPlcItemResults(mapping, allAgLinkItems, true);
if (failedItems.Any())
{
throw new ReadPlcException(validItems, failedItems, $"Some of the items couldn't be read. See the '{nameof(ReadOrWritePlcException.FailedItems)}' property for further information.");
}
}
private static IAGLink4 VerifyConnectivity(AgLinkPlc plc, ICollection <IPlcItem> plcItems, PlcItemUsageType usageType)
{
var underlyingPlc = plc.UnderlyingPlc;
if (underlyingPlc is null)
{
var itemDescriptions = Plc.GetPlcItemDescription(plcItems);
throw new NotConnectedPlcException($"Cannot {usageType.ToString().ToLower()} the plc items ({itemDescriptions}) because {plc:LOG} is not connected. All items will be put on hold.");
}
return(underlyingPlc);
}
