From 130affe4addb1aff1618d8fb849889b2d4453ef2 Mon Sep 17 00:00:00 2001
From: Aaron Seigo <aseigo@kde.org>
Date: Fri, 5 Dec 2014 12:56:33 +0100
Subject: require users of a Storage class to state up-front if they are read
 or readwrite

---
 common/storage.h         |  6 +++---
 common/storage_kyoto.cpp | 25 ++++++++++++++++++-------
 common/storage_lmdb.cpp  | 17 ++++++++++++-----
 3 files changed, 33 insertions(+), 15 deletions(-)

(limited to 'common')

diff --git a/common/storage.h b/common/storage.h
index 0b548fb..846e15b 100644
--- a/common/storage.h
+++ b/common/storage.h
@@ -5,12 +5,12 @@
 
 class Storage {
 public:
-    enum TransactionType { ReadOnly, ReadWrite };
+    enum AccessMode { ReadOnly, ReadWrite };
 
-    Storage(const QString &storageRoot, const QString &name);
+    Storage(const QString &storageRoot, const QString &name, AccessMode mode = ReadOnly);
     ~Storage();
     bool isInTransaction() const;
-    bool startTransaction(TransactionType type = ReadWrite);
+    bool startTransaction(AccessMode mode = ReadWrite);
     bool commitTransaction();
     void abortTransaction();
     bool write(const char *key, size_t keySize, const char *value, size_t valueSize);
diff --git a/common/storage_kyoto.cpp b/common/storage_kyoto.cpp
index 40bd3e6..3d7ab8c 100644
--- a/common/storage_kyoto.cpp
+++ b/common/storage_kyoto.cpp
@@ -15,23 +15,30 @@
 class Storage::Private
 {
 public:
-    Private(const QString &storageRoot, const QString &name);
+    Private(const QString &storageRoot, const QString &name, AccessMode m);
     ~Private();
 
     kyotocabinet::TreeDB db;
+    AccessMode mode;
     bool dbOpen;
     bool inTransaction;
 };
 
-Storage::Private::Private(const QString &storageRoot, const QString &name)
-    : inTransaction(false)
+Storage::Private::Private(const QString &storageRoot, const QString &name, AccessMode m)
+    : mode(m),
+      dbOpen(false),
+      inTransaction(false)
 {
     QDir dir;
     dir.mkdir(storageRoot);
 
     //create file
-    dbOpen = db.open((storageRoot + "/" + name + ".kch").toStdString(), kyotocabinet::BasicDB::OWRITER | kyotocabinet::BasicDB::OCREATE);
+    uint32_t openMode = kyotocabinet::BasicDB::OCREATE |
+                       (mode == ReadOnly ? kyotocabinet::BasicDB::OREADER
+                                         : kyotocabinet::BasicDB::OWRITER);
+    dbOpen = db.open((storageRoot + "/" + name + ".kch").toStdString(), openMode);
     if (!dbOpen) {
+        std::cerr << "Could not open database: " << db.error().codename(db.error().code())  << " " << db.error().message() << std::endl;
         // TODO: handle error
     }
 }
@@ -43,8 +50,8 @@ Storage::Private::~Private()
     }
 }
 
-Storage::Storage(const QString &storageRoot, const QString &name)
-    : d(new Private(storageRoot, name))
+Storage::Storage(const QString &storageRoot, const QString &name, AccessMode mode)
+    : d(new Private(storageRoot, name, mode))
 {
 }
 
@@ -58,12 +65,16 @@ bool Storage::isInTransaction() const
     return d->inTransaction;
 }
 
-bool Storage::startTransaction(TransactionType type)
+bool Storage::startTransaction(AccessMode type)
 {
     if (!d->dbOpen) {
         return false;
     }
 
+    if (type == ReadWrite && d->mode != ReadWrite) {
+        return false;
+    }
+
     if (d->inTransaction) {
         return true;
     }
diff --git a/common/storage_lmdb.cpp b/common/storage_lmdb.cpp
index 8e9b05c..7e23fd3 100644
--- a/common/storage_lmdb.cpp
+++ b/common/storage_lmdb.cpp
@@ -14,7 +14,7 @@
 class Storage::Private
 {
 public:
-    Private(const QString &s, const QString &name);
+    Private(const QString &s, const QString &name, AccessMode m);
     ~Private();
 
     QString storageRoot;
@@ -23,14 +23,16 @@ public:
     MDB_dbi dbi;
     MDB_env *env;
     MDB_txn *transaction;
+    AccessMode mode;
     bool readTransaction;
     bool firstOpen;
 };
 
-Storage::Private::Private(const QString &s, const QString &n)
+Storage::Private::Private(const QString &s, const QString &n, AccessMode m)
     : storageRoot(s),
       name(n),
       transaction(0),
+      mode(m),
       readTransaction(false),
       firstOpen(true)
 {
@@ -65,8 +67,8 @@ Storage::Private::~Private()
     mdb_env_close(env);
 }
 
-Storage::Storage(const QString &storageRoot, const QString &name)
-    : d(new Private(storageRoot, name))
+Storage::Storage(const QString &storageRoot, const QString &name, AccessMode mode)
+    : d(new Private(storageRoot, name, mode))
 {
 }
 
@@ -80,13 +82,18 @@ bool Storage::isInTransaction() const
     return d->transaction;
 }
 
-bool Storage::startTransaction(TransactionType type)
+bool Storage::startTransaction(AccessMode type)
 {
     if (!d->env) {
         return false;
     }
 
     bool requestedRead = type == ReadOnly;
+
+    if (d->mode == ReadOnly && !requestedRead) {
+        return false;
+    }
+
     if (d->transaction && (!d->readTransaction || requestedRead)) {
         return true;
     }
-- 
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