Add new API to convert absolute source paths to relative paths. (#930)

There are already APIs for getting a relative product path from an absolute source path, or getting a relative source path for an *existing* source file, but there were no APIs for getting a relative source path for a *new* source file. Prefabs will need this ability to be able to correctly generate a relative source path inside the prefab file before the file has been saved. The logic for relative source paths is a little bit tricky because the paths are relative to the watch folders, and the watch folders can be nested, with different priorities to explain which should take precedence. The input paths can also include specifiers like "." and "..", which need to be reconciled before creating the final correct relative path. The included unit tests test all of the tricky edge cases that I was able to identify.
2021-05-26 15:30:21 -05:00
parent 0678dec64e
commit 6c17c7bfb3
18 changed files with 446 additions and 9 deletions
@@ -655,6 +655,80 @@ namespace AssetProcessor
        return true;
    }

+    bool AssetCatalog::GenerateRelativeSourcePath(
+        const AZStd::string& sourcePath, AZStd::string& relativePath, AZStd::string& rootFolder)
+    {
+        QString normalizedSourcePath = AssetUtilities::NormalizeFilePath(sourcePath.c_str());
+        QDir inputPath(normalizedSourcePath);
+        QString scanFolder;
+        QString relativeName;
+
+        bool validResult = false;
+
+        AZ_TracePrintf(AssetProcessor::DebugChannel, "ProcessGenerateRelativeSourcePathRequest: %s...\n", sourcePath.c_str());
+
+        if (sourcePath.empty())
+        {
+            // For an empty input path, do nothing, we'll return an empty, invalid result.
+            // (We check fullPath instead of inputPath, because an empty fullPath actually produces "." for inputPath)
+        }
+        else if (inputPath.isAbsolute())
+        {
+            // For an absolute path, try to convert it to a relative path, based on the existing scan folders.
+            // To get the inputPath, we use absolutePath() instead of path() so that any . or .. entries get collapsed.
+            validResult = m_platformConfig->ConvertToRelativePath(inputPath.absolutePath(), relativeName, scanFolder);
+        }
+        else if (inputPath.isRelative())
+        {
+            // For a relative path, concatenate it with each scan folder, and see if a valid relative path emerges.
+            int scanFolders = m_platformConfig->GetScanFolderCount();
+            for (int scanIdx = 0; scanIdx < scanFolders; scanIdx++)
+            {
+                auto& scanInfo = m_platformConfig->GetScanFolderAt(scanIdx);
+                QDir possibleRoot(scanInfo.ScanPath());
+                QDir possibleAbsolutePath = possibleRoot.filePath(normalizedSourcePath);
+                // To get the inputPath, we use absolutePath() instead of path() so that any . or .. entries get collapsed.
+                if (m_platformConfig->ConvertToRelativePath(possibleAbsolutePath.absolutePath(), relativeName, scanFolder))
+                {
+                    validResult = true;
+                    break;
+                }
+            }
+        }
+
+        // The input has produced a valid relative path.  However, the path might match multiple nested scan folders,
+        // so look to see if a higher-priority folder has a better match.
+        if (validResult)
+        {
+            QString overridingFile = m_platformConfig->GetOverridingFile(relativeName, scanFolder);
+
+            if (!overridingFile.isEmpty())
+            {
+                overridingFile = AssetUtilities::NormalizeFilePath(overridingFile);
+                validResult = m_platformConfig->ConvertToRelativePath(overridingFile, relativeName, scanFolder);
+            }
+        }
+
+        if (!validResult)
+        {
+            // if we are here it means we have failed to determine the relativePath, so we will send back the original path
+            AZ_TracePrintf(AssetProcessor::DebugChannel,
+                "GenerateRelativeSourcePath found no valid result, returning original path: %s...\n", sourcePath.c_str());
+
+            rootFolder.clear();
+            relativePath.clear();
+            relativePath = sourcePath;
+            return false;
+        }
+
+        relativePath = relativeName.toUtf8().data();
+        rootFolder = scanFolder.toUtf8().data();
+
+        AZ_Assert(!relativePath.empty(), "ConvertToRelativePath returned true, but relativePath is empty");
+
+        return true;
+    }
+
    bool AssetCatalog::GetFullSourcePathFromRelativeProductPath(const AZStd::string& relPath, AZStd::string& fullSourcePath)
    {
        ProcessGetFullSourcePathFromRelativeProductPathRequest(relPath, fullSourcePath);