80/118: Make readDirectory() return inode / file type

[Ludovic Courtès]

civodul pushed a commit to branch nix
in repository guix.

commit 82d463d9cacbf2a93b95ab5313567d593fd00d02
Author: Eelco Dolstra <address@hidden>
Date:   Fri Aug 1 16:37:47 2014 +0200

    Make readDirectory() return inode / file type
---
 nix/libstore/gc.cc          |   14 ++++++--------
 nix/libstore/local-store.cc |   20 +++++++++-----------
 nix/libutil/archive.cc      |   15 +++++++--------
 nix/libutil/util.cc         |   15 +++++++--------
 nix/libutil/util.hh         |   11 ++++++++++-
 5 files changed, 39 insertions(+), 36 deletions(-)

diff --git a/nix/libstore/gc.cc b/nix/libstore/gc.cc
index e7285fb..e869745 100644
--- a/nix/libstore/gc.cc
+++ b/nix/libstore/gc.cc
@@ -230,11 +230,11 @@ static void readTempRoots(PathSet & tempRoots, FDs & fds)
 {
     /* Read the `temproots' directory for per-process temporary root
        files. */
-    Strings tempRootFiles = readDirectory(
+    DirEntries tempRootFiles = readDirectory(
         (format("%1%/%2%") % settings.nixStateDir % tempRootsDir).str());
 
-    foreach (Strings::iterator, i, tempRootFiles) {
-        Path path = (format("%1%/%2%/%3%") % settings.nixStateDir % 
tempRootsDir % *i).str();
+    for (auto & i : tempRootFiles) {
+        Path path = (format("%1%/%2%/%3%") % settings.nixStateDir % 
tempRootsDir % i.name).str();
 
         debug(format("reading temporary root file `%1%'") % path);
         FDPtr fd(new AutoCloseFD(open(path.c_str(), O_RDWR, 0666)));
@@ -301,9 +301,8 @@ static void findRoots(StoreAPI & store, const Path & path, 
Roots & roots)
         struct stat st = lstat(path);
 
         if (S_ISDIR(st.st_mode)) {
-            Strings names = readDirectory(path);
-            foreach (Strings::iterator, i, names)
-                findRoots(store, path + "/" + *i, roots);
+            for (auto & i : readDirectory(path))
+                findRoots(store, path + "/" + i.name, roots);
         }
 
         else if (S_ISLNK(st.st_mode)) {
@@ -455,7 +454,6 @@ void LocalStore::deletePathRecursive(GCState & state, const 
Path & path)
         // if the path was not valid, need to determine the actual
         // size.
         state.bytesInvalidated += size;
-        // Mac OS X cannot rename directories if they are read-only.
         if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
             throw SysError(format("making `%1%' writable") % path);
         Path tmp = state.trashDir + "/" + baseNameOf(path);
@@ -655,7 +653,7 @@ void LocalStore::collectGarbage(const GCOptions & options, 
GCResults & results)
 
     /* After this point the set of roots or temporary roots cannot
        increase, since we hold locks on everything.  So everything
-       that is not reachable from `roots'. */
+       that is not reachable from `roots' is garbage. */
 
     if (state.shouldDelete) {
         if (pathExists(state.trashDir)) deleteGarbage(state, state.trashDir);
diff --git a/nix/libstore/local-store.cc b/nix/libstore/local-store.cc
index 7d78ab7..c635769 100644
--- a/nix/libstore/local-store.cc
+++ b/nix/libstore/local-store.cc
@@ -593,9 +593,9 @@ static void canonicalisePathMetaData_(const Path & path, 
uid_t fromUid, InodesSe
     }
 
     if (S_ISDIR(st.st_mode)) {
-        Strings names = readDirectory(path);
-        foreach (Strings::iterator, i, names)
-            canonicalisePathMetaData_(path + "/" + *i, fromUid, inodesSeen);
+        DirEntries entries = readDirectory(path);
+        for (auto & i : entries)
+            canonicalisePathMetaData_(path + "/" + i.name, fromUid, 
inodesSeen);
     }
 }
 
@@ -1730,8 +1730,8 @@ bool LocalStore::verifyStore(bool checkContents, bool 
repair)
     /* Acquire the global GC lock to prevent a garbage collection. */
     AutoCloseFD fdGCLock = openGCLock(ltWrite);
 
-    Paths entries = readDirectory(settings.nixStore);
-    PathSet store(entries.begin(), entries.end());
+    PathSet store;
+    for (auto & i : readDirectory(settings.nixStore)) store.insert(i.name);
 
     /* Check whether all valid paths actually exist. */
     printMsg(lvlInfo, "checking path existence...");
@@ -1881,9 +1881,8 @@ void LocalStore::markContentsGood(const Path & path)
 PathSet LocalStore::queryValidPathsOld()
 {
     PathSet paths;
-    Strings entries = readDirectory(settings.nixDBPath + "/info");
-    foreach (Strings::iterator, i, entries)
-        if (i->at(0) != '.') paths.insert(settings.nixStore + "/" + *i);
+    for (auto & i : readDirectory(settings.nixDBPath + "/info"))
+        if (i.name.at(0) != '.') paths.insert(settings.nixStore + "/" + 
i.name);
     return paths;
 }
 
@@ -1970,9 +1969,8 @@ static void makeMutable(const Path & path)
     if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) return;
 
     if (S_ISDIR(st.st_mode)) {
-        Strings names = readDirectory(path);
-        foreach (Strings::iterator, i, names)
-            makeMutable(path + "/" + *i);
+        for (auto & i : readDirectory(path))
+            makeMutable(path + "/" + i.name);
     }
 
     /* The O_NOFOLLOW is important to prevent us from changing the
diff --git a/nix/libutil/archive.cc b/nix/libutil/archive.cc
index 5450fd2..6856ea0 100644
--- a/nix/libutil/archive.cc
+++ b/nix/libutil/archive.cc
@@ -83,22 +83,21 @@ static void dump(const Path & path, Sink & sink, PathFilter 
& filter)
 
         /* If we're on a case-insensitive system like Mac OS X, undo
            the case hack applied by restorePath(). */
-        Strings names = readDirectory(path);
         std::map<string, string> unhacked;
-        for (auto & i : names)
+        for (auto & i : readDirectory(path))
             if (useCaseHack) {
-                string name(i);
-                size_t pos = i.find(caseHackSuffix);
+                string name(i.name);
+                size_t pos = i.name.find(caseHackSuffix);
                 if (pos != string::npos) {
-                    printMsg(lvlDebug, format("removing case hack suffix from 
`%1%'") % (path + "/" + i));
+                    printMsg(lvlDebug, format("removing case hack suffix from 
`%1%'") % (path + "/" + i.name));
                     name.erase(pos);
                 }
                 if (unhacked.find(name) != unhacked.end())
                     throw Error(format("file name collision in between `%1%' 
and `%2%'")
-                        % (path + "/" + unhacked[name]) % (path + "/" + i));
-                unhacked[name] = i;
+                        % (path + "/" + unhacked[name]) % (path + "/" + 
i.name));
+                unhacked[name] = i.name;
             } else
-                unhacked[i] = i;
+                unhacked[i.name] = i.name;
 
         for (auto & i : unhacked)
             if (filter(path + "/" + i.first)) {
diff --git a/nix/libutil/util.cc b/nix/libutil/util.cc
index aa9d99e..3f9c697 100644
--- a/nix/libutil/util.cc
+++ b/nix/libutil/util.cc
@@ -203,9 +203,10 @@ bool isLink(const Path & path)
 }
 
 
-Strings readDirectory(const Path & path)
+DirEntries readDirectory(const Path & path)
 {
-    Strings names;
+    DirEntries entries;
+    entries.reserve(64);
 
     AutoCloseDir dir = opendir(path.c_str());
     if (!dir) throw SysError(format("opening directory `%1%'") % path);
@@ -215,11 +216,11 @@ Strings readDirectory(const Path & path)
         checkInterrupt();
         string name = dirent->d_name;
         if (name == "." || name == "..") continue;
-        names.push_back(name);
+        entries.emplace_back(DirEntry({ name, dirent->d_ino, dirent->d_type 
}));
     }
     if (errno) throw SysError(format("reading directory `%1%'") % path);
 
-    return names;
+    return entries;
 }
 
 
@@ -294,16 +295,14 @@ static void _deletePath(const Path & path, unsigned long 
long & bytesFreed)
         bytesFreed += st.st_blocks * 512;
 
     if (S_ISDIR(st.st_mode)) {
-        Strings names = readDirectory(path);
-
         /* Make the directory writable. */
         if (!(st.st_mode & S_IWUSR)) {
             if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
                 throw SysError(format("making `%1%' writable") % path);
         }
 
-        for (Strings::iterator i = names.begin(); i != names.end(); ++i)
-            _deletePath(path + "/" + *i, bytesFreed);
+        for (auto & i : readDirectory(path))
+            _deletePath(path + "/" + i.name, bytesFreed);
     }
 
     if (remove(path.c_str()) == -1)
diff --git a/nix/libutil/util.hh b/nix/libutil/util.hh
index ad0d377..462b98e 100644
--- a/nix/libutil/util.hh
+++ b/nix/libutil/util.hh
@@ -64,7 +64,16 @@ bool isLink(const Path & path);
 
 /* Read the contents of a directory.  The entries `.' and `..' are
    removed. */
-Strings readDirectory(const Path & path);
+struct DirEntry
+{
+    string name;
+    ino_t ino;
+    unsigned char type; // one of DT_*
+};
+
+typedef vector<DirEntry> DirEntries;
+
+DirEntries readDirectory(const Path & path);
 
 /* Read the contents of a file into a string. */
 string readFile(int fd);