reapack

commit 2156cf690ae00e165bd063811432055005b79912
parent 14ccc6444ec29e73469e98b7477e2a30198b9751
Author: cfillion <cfillion@users.noreply.github.com>
Date:   Sat, 12 Dec 2015 20:19:17 -0500

save downloaded files under a temporary name first

Diffstat:
M
src/path.cpp
 | 
15
+++++++++++++++
M
src/path.hpp
 | 
2
++
M
src/transaction.cpp
 | 
63
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
M
src/transaction.hpp
 | 
13
++++++++++---
M
test/path.cpp
 | 
17
+++++++++++++++++

5 files changed, 101 insertions(+), 9 deletions(-)
diff --git a/src/path.cpp b/src/path.cpp
@@ -20,6 +20,11 @@ void Path::append(const string &part)
     m_parts.push_back(part);
 }
 
+void Path::clear()
+{
+  m_parts.clear();
+}
+
 string Path::basename() const
 {
   if(m_parts.empty())
@@ -74,3 +79,13 @@ Path Path::operator+(const Path &o) const
 
   return path;
 }
+
+string &Path::operator[](const size_t index)
+{
+  auto it = m_parts.begin();
+
+  for(size_t i = 0; i < index; i++)
+    it++;
+
+  return *it;
+}
diff --git a/src/path.hpp b/src/path.hpp
@@ -8,6 +8,7 @@ class Path {
 public:
   void prepend(const std::string &part);
   void append(const std::string &part);
+  void clear();
 
   bool empty() const { return m_parts.empty(); }
   size_t size() const { return m_parts.size(); }
@@ -20,6 +21,7 @@ public:
   bool operator!=(const Path &) const;
   Path operator+(const std::string &) const;
   Path operator+(const Path &) const;
+  std::string &operator[](const size_t index);
 
 private:
   std::string join(const bool) const;
diff --git a/src/transaction.cpp b/src/transaction.cpp
@@ -2,6 +2,7 @@
 
 #include "errors.hpp"
 
+#include <cstdio>
 #include <fstream>
 
 #include <reaper_plugin_functions.h>
@@ -12,6 +13,7 @@ Transaction::Transaction(Registry *reg, const Path &root)
   : m_registry(reg), m_root(root), m_isCancelled(false)
 {
   m_dbPath = m_root + "ReaPack";
+
   RecursiveCreateDirectory(m_dbPath.join().c_str(), 0);
 }
 
@@ -116,6 +118,10 @@ void Transaction::run()
 void Transaction::cancel()
 {
   m_isCancelled = true;
+
+  for(PackageTransaction *tr : m_transactions)
+    tr->cancel();
+
   m_queue.abort();
 }
 
@@ -147,6 +153,11 @@ void Transaction::finish()
   if(!m_queue.idle())
     return;
 
+  if(!m_isCancelled) {
+    for(PackageTransaction *tr : m_transactions)
+      tr->apply();
+  }
+
   m_onFinish();
 }
 
@@ -155,6 +166,11 @@ void Transaction::addError(const string &message, const string &title)
   m_errors.push_back({message, title});
 }
 
+Path Transaction::prefixPath(const Path &input) const
+{
+  return m_root + input;
+}
+
 bool PackageTransaction::isInstalled(Version *ver, const Path &root)
 {
   // TODO
@@ -163,7 +179,7 @@ bool PackageTransaction::isInstalled(Version *ver, const Path &root)
 }
 
 PackageTransaction::PackageTransaction(Transaction *transaction)
-  : m_transaction(transaction), m_remaining(0)
+  : m_transaction(transaction), m_isCancelled(false)
 {
 }
 
@@ -190,10 +206,19 @@ void PackageTransaction::saveSource(Download *dl, Source *src)
 {
   m_remaining.erase(remove(m_remaining.begin(), m_remaining.end(), dl));
 
-  const Path path = installPath(src);
+  if(m_isCancelled)
+    return;
+
+  const Path targetPath = src->targetPath();
+  Path tmpPath = targetPath;
+  tmpPath[tmpPath.size() - 1] += ".new";
+
+  m_files.push({tmpPath, targetPath});
+
+  const Path path = m_transaction->prefixPath(tmpPath);
 
   if(!m_transaction->saveFile(dl, path)) {
-    abort();
+    cancel();
     return;
   }
 }
@@ -206,13 +231,39 @@ void PackageTransaction::finish()
   m_onFinish();
 }
 
-void PackageTransaction::abort()
+void PackageTransaction::cancel()
 {
+  m_isCancelled = true;
+
   for(Download *dl : m_remaining)
     dl->abort();
+
+  rollback();
+}
+
+void PackageTransaction::apply()
+{
+  while(!m_files.empty()) {
+    const PathPair paths = m_files.front();
+    m_files.pop();
+
+    const string tempPath = m_transaction->prefixPath(paths.first).join();
+    const string targetPath = m_transaction->prefixPath(paths.second).join();
+
+    if(rename(tempPath.c_str(), targetPath.c_str()))
+      m_transaction->addError(strerror(errno), targetPath);
+  }
 }
 
-Path PackageTransaction::installPath(Source *src) const
+void PackageTransaction::rollback()
 {
-  return m_transaction->m_root + src->targetPath();
+  while(!m_files.empty()) {
+    const PathPair paths = m_files.front();
+    m_files.pop();
+
+    const string tempPath = m_transaction->prefixPath(paths.first).join();
+
+    if(remove(tempPath.c_str()))
+      m_transaction->addError(strerror(errno), tempPath);
+  }
 }
diff --git a/src/transaction.hpp b/src/transaction.hpp
@@ -8,6 +8,7 @@
 #include "remote.hpp"
 
 #include <boost/signals2.hpp>
+#include <queue>
 
 class PackageTransaction;
 
@@ -53,6 +54,7 @@ private:
   void saveDatabase(Download *);
   bool saveFile(Download *, const Path &);
   void addError(const std::string &msg, const std::string &title);
+  Path prefixPath(const Path &) const;
 
   Registry *m_registry;
 
@@ -85,16 +87,21 @@ public:
   void onFinish(const Callback &callback) { m_onFinish.connect(callback); }
 
   void install(Version *ver);
-  void abort();
+  void apply();
+  void cancel();
 
 private:
-  void saveSource(Download *, Source *);
-  Path installPath(Source *) const;
+  typedef std::pair<Path, Path> PathPair;
 
   void finish();
+  void rollback();
+
+  void saveSource(Download *, Source *);
 
   Transaction *m_transaction;
+  bool m_isCancelled;
   std::vector<Download *> m_remaining;
+  std::queue<PathPair> m_files;
 
   Signal m_onFinish;
 };
diff --git a/test/path.cpp b/test/path.cpp
@@ -78,3 +78,20 @@ TEST_CASE("empty components", M) {
 
   REQUIRE(a.size() == 0);
 }
+
+TEST_CASE("clear path", M) {
+  Path a;
+  a.append("test");
+
+  CHECK(a.size() == 1);
+  a.clear();
+  REQUIRE(a.size() == 0);
+}
+
+TEST_CASE("modify path", M) {
+  Path a;
+  a.append("hello");
+
+  a[0] = "world";
+  REQUIRE(a.join() == "world");
+}