1 files changed, 186 insertions, 0 deletions
diff --git a/contrib/llvm/tools/lldb/source/Utility/ModuleCache.cpp b/contrib/llvm/tools/lldb/source/Utility/ModuleCache.cpp
new file mode 100644
index 0000000..ce0df24
--- /dev/null
+++ b/contrib/llvm/tools/lldb/source/Utility/ModuleCache.cpp
@@ -0,0 +1,186 @@
+//===--------------------- ModuleCache.cpp ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ModuleCache.h"
+
+#include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleSpec.h"
+#include "lldb/Host/File.h"
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Host/LockFile.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FileUtilities.h"
+
+#include <assert.h>
+
+#include <cstdio>
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+const char* kModulesSubdir = ".cache";
+const char* kLockFileName = ".lock";
+const char* kTempFileName = ".temp";
+
+FileSpec
+JoinPath (const FileSpec &path1, const char* path2)
+{
+    FileSpec result_spec (path1);
+    result_spec.AppendPathComponent (path2);
+    return result_spec;
+}
+
+Error
+MakeDirectory (const FileSpec &dir_path)
+{
+    if (dir_path.Exists ())
+    {
+        if (!dir_path.IsDirectory ())
+            return Error ("Invalid existing path");
+
+        return Error ();
+    }
+
+    return FileSystem::MakeDirectory(dir_path, eFilePermissionsDirectoryDefault);
+}
+
+FileSpec
+GetModuleDirectory (const FileSpec &root_dir_spec, const UUID &uuid)
+{
+    const auto modules_dir_spec = JoinPath (root_dir_spec, kModulesSubdir);
+    return JoinPath (modules_dir_spec, uuid.GetAsString ().c_str ());
+}
+
+Error
+CreateHostSysRootModuleLink (const FileSpec &root_dir_spec, const char *hostname, const FileSpec &platform_module_spec, const FileSpec &local_module_spec)
+{
+    const auto sysroot_module_path_spec = JoinPath (
+        JoinPath (root_dir_spec, hostname), platform_module_spec.GetPath ().c_str ());
+    if (sysroot_module_path_spec.Exists())
+        return Error ();
+
+    const auto error = MakeDirectory (FileSpec (sysroot_module_path_spec.GetDirectory ().AsCString (), false));
+    if (error.Fail ())
+        return error;
+
+    return FileSystem::Hardlink(sysroot_module_path_spec, local_module_spec);
+}
+
+}  // namespace
+
+Error
+ModuleCache::Put (const FileSpec &root_dir_spec,
+                  const char *hostname,
+                  const ModuleSpec &module_spec,
+                  const FileSpec &tmp_file)
+{
+    const auto module_spec_dir = GetModuleDirectory (root_dir_spec, module_spec.GetUUID ());
+    const auto module_file_path = JoinPath (module_spec_dir, module_spec.GetFileSpec ().GetFilename ().AsCString ());
+
+    const auto tmp_file_path = tmp_file.GetPath ();
+    const auto err_code = llvm::sys::fs::rename (tmp_file_path.c_str (), module_file_path.GetPath ().c_str ());
+    if (err_code)
+        return Error ("Failed to rename file %s to %s: %s",
+                      tmp_file_path.c_str (), module_file_path.GetPath ().c_str (), err_code.message ().c_str ());
+
+    const auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname, module_spec.GetFileSpec(), module_file_path);
+    if (error.Fail ())
+        return Error ("Failed to create link to %s: %s", module_file_path.GetPath ().c_str (), error.AsCString ());
+    return Error ();
+}
+
+Error
+ModuleCache::Get (const FileSpec &root_dir_spec,
+                  const char *hostname,
+                  const ModuleSpec &module_spec,
+                  ModuleSP &cached_module_sp,
+                  bool *did_create_ptr)
+{
+    const auto find_it = m_loaded_modules.find (module_spec.GetUUID ().GetAsString());
+    if (find_it != m_loaded_modules.end ())
+    {
+        cached_module_sp = (*find_it).second.lock ();
+        if (cached_module_sp)
+            return Error ();
+        m_loaded_modules.erase (find_it);
+    }
+
+    const auto module_spec_dir = GetModuleDirectory (root_dir_spec, module_spec.GetUUID ());
+    const auto module_file_path = JoinPath (module_spec_dir, module_spec.GetFileSpec ().GetFilename ().AsCString ());
+
+    if (!module_file_path.Exists ())
+        return Error ("Module %s not found", module_file_path.GetPath ().c_str ());
+    if (module_file_path.GetByteSize () != module_spec.GetObjectSize ())
+        return Error ("Module %s has invalid file size", module_file_path.GetPath ().c_str ());
+
+    // We may have already cached module but downloaded from an another host - in this case let's create a link to it.
+    const auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname, module_spec.GetFileSpec(), module_file_path);
+    if (error.Fail ())
+        return Error ("Failed to create link to %s: %s", module_file_path.GetPath().c_str(), error.AsCString());
+
+    auto cached_module_spec (module_spec);
+    cached_module_spec.GetUUID ().Clear ();  // Clear UUID since it may contain md5 content hash instead of real UUID.
+    cached_module_spec.GetFileSpec () = module_file_path;
+    cached_module_spec.GetPlatformFileSpec () = module_spec.GetFileSpec ();
+    cached_module_sp.reset (new Module (cached_module_spec));
+    if (did_create_ptr)
+        *did_create_ptr = true;
+
+    m_loaded_modules.insert (std::make_pair (module_spec.GetUUID ().GetAsString (), cached_module_sp));
+
+    return Error ();
+}
+
+Error
+ModuleCache::GetAndPut (const FileSpec &root_dir_spec,
+                        const char *hostname,
+                        const ModuleSpec &module_spec,
+                        const Downloader &downloader,
+                        lldb::ModuleSP &cached_module_sp,
+                        bool *did_create_ptr)
+{
+    const auto module_spec_dir = GetModuleDirectory (root_dir_spec, module_spec.GetUUID ());
+    auto error = MakeDirectory (module_spec_dir);
+    if (error.Fail ())
+        return error;
+
+    // Open lock file.
+    const auto lock_file_spec = JoinPath (module_spec_dir, kLockFileName);
+    File lock_file (lock_file_spec, File::eOpenOptionWrite | File::eOpenOptionCanCreate | File::eOpenOptionCloseOnExec);
+    if (!lock_file)
+    {
+        error.SetErrorToErrno ();
+        return Error("Failed to open lock file %s: %s", lock_file_spec.GetPath ().c_str (), error.AsCString ());
+    }
+    LockFile lock (lock_file.GetDescriptor ());
+    error = lock.WriteLock (0, 1);
+    if (error.Fail ())
+        return Error("Failed to lock file %s:%s", lock_file_spec.GetPath ().c_str (), error.AsCString ());
+
+    // Check local cache for a module.
+    error = Get (root_dir_spec, hostname, module_spec, cached_module_sp, did_create_ptr);
+    if (error.Success ())
+        return error;
+
+    const auto tmp_download_file_spec = JoinPath (module_spec_dir, kTempFileName);
+    error = downloader (module_spec, tmp_download_file_spec);
+    llvm::FileRemover tmp_file_remover (tmp_download_file_spec.GetPath ().c_str ());
+    if (error.Fail ())
+        return Error("Failed to download module: %s", error.AsCString ());
+
+    // Put downloaded file into local module cache.
+    error = Put (root_dir_spec, hostname, module_spec, tmp_download_file_spec);
+    if (error.Fail ())
+        return Error ("Failed to put module into cache: %s", error.AsCString ());
+
+    tmp_file_remover.releaseFile ();
+    return Get (root_dir_spec, hostname, module_spec, cached_module_sp, did_create_ptr);
+}