[main] Rearrange some code in RootObjTree

Author: silverweed

main/src/RootObjTree.cxx

@@ -114,33 +114,52 @@ ROOT::CmdLine::GetMatchingPathsInFile(std::string_view fileName, std::string_vie
    return source;
 }
 
-ROOT::CmdLine::RootSource ROOT::CmdLine::ParseRootSource(std::string_view sourceRaw, std::uint32_t flags)
+ROOT::RResult<std::pair<std::string_view, std::string_view>>
+ROOT::CmdLine::SplitIntoFileNameAndPattern(std::string_view sourceRaw)
 {
-   ROOT::CmdLine::RootSource source;
-   const char *str = sourceRaw.data();
-
-   // Handle known URI prefixes
-   static const char *const specialPrefixes[] = {"http", "https", "root", "gs", "s3"};
-   for (const char *prefix : specialPrefixes) {
-      const auto prefixLen = strlen(prefix);
-      if (strncmp(str, prefix, prefixLen) == 0 && strncmp(str + prefixLen, "://", 3) == 0) {
-         source.fFileName = std::string(prefix) + "://";
-         str += prefixLen + 3;
-         break;
+   auto prefixIdx = sourceRaw.find("://");
+   std::string_view::size_type separatorIdx = 0;
+   if (prefixIdx != std::string_view::npos) {
+      bool prefixFound = false;
+      // Handle known URI prefixes
+      static const char *const specialPrefixes[] = {"http", "https", "root", "gs", "s3"};
+      auto prefix = sourceRaw.substr(0, prefixIdx);
+      for (std::string_view knownPrefix : specialPrefixes) {
+         if (prefix == knownPrefix) {
+            prefixFound = true;
+            break;
+         }
+      }
+      if (!prefixFound) {
+         return R__FAIL("unknown file protocol");
       }
+      separatorIdx = sourceRaw.substr(prefixIdx + 3).find_first_of(':');
+      if (separatorIdx != std::string_view::npos)
+         separatorIdx += prefixIdx + 3;
+   } else {
+      separatorIdx = sourceRaw.find_first_of(':');
    }
 
-   auto tokens = ROOT::Split(str, ":");
-   if (tokens.empty())
-      return source;
+   if (separatorIdx != std::string_view::npos) {
+      return {{sourceRaw.substr(0, separatorIdx), sourceRaw.substr(separatorIdx + 1)}};
+   }
+   return {{sourceRaw, std::string_view{}}};
+}
 
-   source.fFileName += tokens[0];
-   if (tokens.size() > 1) {
-      source = ROOT::CmdLine::GetMatchingPathsInFile(source.fFileName, tokens[1], flags);
-   } else {
-      source = ROOT::CmdLine::GetMatchingPathsInFile(source.fFileName, "", flags);
+ROOT::CmdLine::RootSource ROOT::CmdLine::ParseRootSource(std::string_view sourceRaw, std::uint32_t flags)
+{
+   ROOT::CmdLine::RootSource source;
+
+   auto res = SplitIntoFileNameAndPattern(sourceRaw);
+   if (!res) {
+      source.fErrors.push_back(res.GetError()->GetReport());
+      return source;
    }
 
+   auto [fileName, tokens] = res.Unwrap();
+   source = ROOT::CmdLine::GetMatchingPathsInFile(fileName, tokens, flags);
+
+   assert(source.fErrors.empty() == !!source.fObjectTree.fFile);
    return source;
 }
 

main/src/RootObjTree.hxx

@@ -12,12 +12,15 @@
 #define ROOT_CMDLINE_OBJTREE
 
 #include <cstdint>
+#include <iostream>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include <TKey.h>
 
+#include <ROOT/RError.hxx>
+
 class TDirectory;
 class TFile;
 
@@ -50,7 +53,9 @@ inline RootObjNode NodeFromKey(TKey &key)
 struct RootObjTree {
    // 0th node is the root node
    std::vector<RootObjNode> fNodes;
+   // All nodes in fNodes that are dirs
    std::vector<NodeIdx_t> fDirList;
+   // All nodes in fNodes that are leaves (non-TDirectories)
    std::vector<NodeIdx_t> fLeafList;
    // The file must be kept alive in order to access the nodes' keys
    std::unique_ptr<TFile> fFile;
@@ -85,6 +90,10 @@ enum EGetMatchingPathsFlags {
 /// \param flags A bitmask of EGetMatchingPathsFlags
 RootSource GetMatchingPathsInFile(std::string_view fileName, std::string_view pattern, std::uint32_t flags);
 
+/// Given a string like "root://file.root:a/b/c", splits it into { "root://file.root", "a/b/c" }.
+/// \return An error if the file prefix is unknown (e.g. "foo://file.root"), otherwise the result described above.
+ROOT::RResult<std::pair<std::string_view, std::string_view>> SplitIntoFileNameAndPattern(std::string_view sourceRaw);
+
 /// Given a string like "file.root:dir/obj", converts it to a RootSource.
 /// The string may start with one of the known file protocols: "http", "https", "root", "gs", "s3"
 /// (e.g. "https://file.root").

main/src/rootls.cxx

@@ -509,26 +509,6 @@ static void PrintChildrenInColumns(std::ostream &stream, const RootObjTree &tree
    PrintNodesInColumns(stream, tree, children.begin(), children.end(), flags, indent);
 }
 
-static std::string NodeFullPath(const RootObjTree &tree, NodeIdx_t nodeIdx)
-{
-   std::vector<const std::string *> fragments;
-   const RootObjNode *node = &tree.fNodes[nodeIdx];
-   NodeIdx_t prevParent;
-   do {
-      prevParent = node->fParent;
-      fragments.push_back(&node->fName);
-      node = &tree.fNodes[node->fParent];
-   } while (node->fParent != prevParent);
-
-   assert(!fragments.empty());
-
-   std::string fullPath = **fragments.rbegin();
-   for (auto it = std::next(fragments.rbegin()), end = fragments.rend(); it != end; ++it) {
-      fullPath += '/' + **it;
-   }
-   return fullPath;
-}
-
 // Main entrypoint of the program
 static void RootLs(const RootLsArgs &args, std::ostream &stream = std::cout)
 {