libstore: move LocalStoreAccessor definition to header

That way it's possible to inherit from LocalStoreAccessor to implement
special behavior such as an accessor that falls back to the chroot
directory if it can't find a store-path (which is what we'll do in the
next commit).

Change-Id: If689eb3f410e81e629f1d13cc2b48594fecb1001

lix/libstore/local-fs-store.cc

@@ -2,82 +2,83 @@
 #include "lix/libstore/fs-accessor.hh"
 #include "lix/libstore/store-api.hh"
 #include "lix/libstore/local-fs-store.hh"
-#include "lix/libstore/globals.hh"
 #include "lix/libutil/async-io.hh"
 #include "lix/libutil/compression.hh"
-#include "lix/libstore/derivations.hh"
+#include "lix/libutil/file-system.hh"
+#include "lix/libutil/result.hh"
 
 namespace nix {
 
-struct LocalStoreAccessor : public FSAccessor
-{
-    ref<LocalFSStore> store;
-
-    LocalStoreAccessor(ref<LocalFSStore> store) : store(store) { }
-
-    kj::Promise<Result<Path>> toRealPath(const Path & path, bool requireValidPath = true)
-    try {
-        auto storePath = store->toStorePath(path).first;
-        if (requireValidPath && !TRY_AWAIT(store->isValidPath(storePath)))
-            throw InvalidPath("path '%1%' does not exist in the store", store->printStorePath(storePath));
-        co_return store->getRealStoreDir() + std::string(path, store->config().storeDir.size());
-    } catch (...) {
-        co_return result::current_exception();
+kj::Promise<Result<Path>> LocalStoreAccessor::toRealPath(const Path & path, bool requireValidPath)
+try {
+    auto storePath = store->toStorePath(path).first;
+    if (requireValidPath && !TRY_AWAIT(store->isValidPath(storePath))) {
+        throw InvalidPath(
+            "path '%1%' does not exist in the store", store->printStorePath(storePath)
+        );
     }
+    co_return store->getRealStoreDir() + std::string(path, store->config().storeDir.size());
+} catch (...) {
+    co_return result::current_exception();
+}
 
-    kj::Promise<Result<FSAccessor::Stat>> stat(const Path & path) override
-    try {
-        auto realPath = TRY_AWAIT(toRealPath(path));
+kj::Promise<Result<FSAccessor::Stat>> LocalStoreAccessor::stat(const Path & path)
+try {
+    auto realPath = TRY_AWAIT(toRealPath(path));
 
-        struct stat st;
-        if (lstat(realPath.c_str(), &st)) {
-            if (errno == ENOENT || errno == ENOTDIR) co_return {Type::tMissing, 0, false};
-            throw SysError("getting status of '%1%'", path);
+    struct stat st;
+    if (lstat(realPath.c_str(), &st)) {
+        if (errno == ENOENT || errno == ENOTDIR) {
+            co_return {Type::tMissing, 0, false};
         }
-
-        if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode))
-            throw Error("file '%1%' has unsupported type", path);
-
-        co_return {
-            S_ISREG(st.st_mode) ? Type::tRegular :
-            S_ISLNK(st.st_mode) ? Type::tSymlink :
-            Type::tDirectory,
-            S_ISREG(st.st_mode) ? (uint64_t) st.st_size : 0,
-            S_ISREG(st.st_mode) && st.st_mode & S_IXUSR};
-    } catch (...) {
-        co_return result::current_exception();
+        throw SysError("getting status of '%1%'", path);
     }
 
-    kj::Promise<Result<StringSet>> readDirectory(const Path & path) override
-    try {
-        auto realPath = TRY_AWAIT(toRealPath(path));
-
-        auto entries = nix::readDirectory(realPath);
-
-        StringSet res;
-        for (auto & entry : entries)
-            res.insert(entry.name);
-
-        co_return res;
-    } catch (...) {
-        co_return result::current_exception();
+    if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode)) {
+        throw Error("file '%1%' has unsupported type", path);
     }
 
-    kj::Promise<Result<std::string>>
-    readFile(const Path & path, bool requireValidPath = true) override
-    try {
-        co_return nix::readFile(TRY_AWAIT(toRealPath(path, requireValidPath)));
-    } catch (...) {
-        co_return result::current_exception();
+    co_return {
+        S_ISREG(st.st_mode)       ? Type::tRegular
+            : S_ISLNK(st.st_mode) ? Type::tSymlink
+                                  : Type::tDirectory,
+        S_ISREG(st.st_mode) ? (uint64_t) st.st_size : 0,
+        S_ISREG(st.st_mode) && st.st_mode & S_IXUSR
+    };
+} catch (...) {
+    co_return result::current_exception();
+}
+
+kj::Promise<Result<StringSet>> LocalStoreAccessor::readDirectory(const Path & path)
+try {
+    auto realPath = TRY_AWAIT(toRealPath(path));
+
+    auto entries = nix::readDirectory(realPath);
+
+    StringSet res;
+    for (auto & entry : entries) {
+        res.insert(entry.name);
     }
 
-    kj::Promise<Result<std::string>> readLink(const Path & path) override
-    try {
-        co_return nix::readLink(TRY_AWAIT(toRealPath(path)));
-    } catch (...) {
-        co_return result::current_exception();
-    }
-};
+    co_return res;
+} catch (...) {
+    co_return result::current_exception();
+}
+
+kj::Promise<Result<std::string>>
+LocalStoreAccessor::readFile(const Path & path, bool requireValidPath)
+try {
+    co_return nix::readFile(TRY_AWAIT(toRealPath(path, requireValidPath)));
+} catch (...) {
+    co_return result::current_exception();
+}
+
+kj::Promise<Result<std::string>> LocalStoreAccessor::readLink(const Path & path)
+try {
+    co_return nix::readLink(TRY_AWAIT(toRealPath(path)));
+} catch (...) {
+    co_return result::current_exception();
+}
 
 ref<FSAccessor> LocalFSStore::getFSAccessor()
 {

lix/libstore/local-fs-store.hh

@@ -1,6 +1,7 @@
 #pragma once
 ///@file
 
+#include "fs-accessor.hh"
 #include "lix/libstore/store-api.hh"
 #include "lix/libstore/gc-store.hh"
 #include "lix/libstore/log-store.hh"
@@ -76,4 +77,21 @@ public:
 
 };
 
+struct LocalStoreAccessor : public FSAccessor
+{
+    ref<LocalFSStore> store;
+
+    LocalStoreAccessor(ref<LocalFSStore> store) : store(store) {}
+
+    virtual kj::Promise<Result<Path>> toRealPath(const Path & path, bool requireValidPath = true);
+
+    kj::Promise<Result<FSAccessor::Stat>> stat(const Path & path) override;
+
+    kj::Promise<Result<StringSet>> readDirectory(const Path & path) override;
+
+    kj::Promise<Result<std::string>>
+    readFile(const Path & path, bool requireValidPath = true) override;
+
+    kj::Promise<Result<std::string>> readLink(const Path & path) override;
+};
 }