update to latest object store code

This commit is contained in:
Ari Lazier 2015-09-28 15:47:32 -07:00
commit d88b089b9f
10 changed files with 1204 additions and 1 deletions

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#include "external_commit_helper.hpp"
#include "shared_realm.hpp"
#include <assert.h>
#include <sys/event.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <system_error>
#include <fcntl.h>
#include <unistd.h>
#include <sstream>
using namespace realm;
namespace {
// Write a byte to a pipe to notify anyone waiting for data on the pipe
void notify_fd(int fd)
{
while (true) {
char c = 0;
ssize_t ret = write(fd, &c, 1);
if (ret == 1) {
break;
}
// If the pipe's buffer is full, we need to read some of the old data in
// it to make space. We don't just read in the code waiting for
// notifications so that we can notify multiple waiters with a single
// write.
assert(ret == -1 && errno == EAGAIN);
char buff[1024];
read(fd, buff, sizeof buff);
}
}
} // anonymous namespace
void ExternalCommitHelper::FdHolder::close()
{
if (m_fd != -1) {
::close(m_fd);
}
m_fd = -1;
}
// Inter-thread and inter-process notifications of changes are done using a
// named pipe in the filesystem next to the Realm file. Everyone who wants to be
// notified of commits waits for data to become available on the pipe, and anyone
// who commits a write transaction writes data to the pipe after releasing the
// write lock. Note that no one ever actually *reads* from the pipe: the data
// actually written is meaningless, and trying to read from a pipe from multiple
// processes at once is fraught with race conditions.
// When a RLMRealm instance is created, we add a CFRunLoopSource to the current
// thread's runloop. On each cycle of the run loop, the run loop checks each of
// its sources for work to do, which in the case of CFRunLoopSource is just
// checking if CFRunLoopSourceSignal has been called since the last time it ran,
// and if so invokes the function pointer supplied when the source is created,
// which in our case just invokes `[realm handleExternalChange]`.
// Listening for external changes is done using kqueue() on a background thread.
// kqueue() lets us efficiently wait until the amount of data which can be read
// from one or more file descriptors has changed, and tells us which of the file
// descriptors it was that changed. We use this to wait on both the shared named
// pipe, and a local anonymous pipe. When data is written to the named pipe, we
// signal the runloop source and wake up the target runloop, and when data is
// written to the anonymous pipe the background thread removes the runloop
// source from the runloop and and shuts down.
ExternalCommitHelper::ExternalCommitHelper(Realm* realm)
{
add_realm(realm);
m_kq = kqueue();
if (m_kq == -1) {
throw std::system_error(errno, std::system_category());
}
auto path = realm->config().path + ".note";
// Create and open the named pipe
int ret = mkfifo(path.c_str(), 0600);
if (ret == -1) {
int err = errno;
if (err == ENOTSUP) {
// Filesystem doesn't support named pipes, so try putting it in tmp instead
// Hash collisions are okay here because they just result in doing
// extra work, as opposed to correctness problems
std::ostringstream ss;
ss << getenv("TMPDIR");
ss << "realm_" << std::hash<std::string>()(path) << ".note";
path = ss.str();
ret = mkfifo(path.c_str(), 0600);
err = errno;
}
// the fifo already existing isn't an error
if (ret == -1 && err != EEXIST) {
throw std::system_error(err, std::system_category());
}
}
m_notify_fd = open(path.c_str(), O_RDWR);
if (m_notify_fd == -1) {
throw std::system_error(errno, std::system_category());
}
// Make writing to the pipe return -1 when the pipe's buffer is full
// rather than blocking until there's space available
ret = fcntl(m_notify_fd, F_SETFL, O_NONBLOCK);
if (ret == -1) {
throw std::system_error(errno, std::system_category());
}
// Create the anonymous pipe
int pipeFd[2];
ret = pipe(pipeFd);
if (ret == -1) {
throw std::system_error(errno, std::system_category());
}
m_shutdown_read_fd = pipeFd[0];
m_shutdown_write_fd = pipeFd[1];
// Use the minimum allowed stack size, as we need very little in our listener
// https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/Multithreading/CreatingThreads/CreatingThreads.html#//apple_ref/doc/uid/10000057i-CH15-SW7
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 16 * 1024);
auto fn = [](void *self) -> void * {
static_cast<ExternalCommitHelper *>(self)->listen();
return nullptr;
};
ret = pthread_create(&m_thread, &attr, fn, this);
pthread_attr_destroy(&attr);
if (ret != 0) {
throw std::system_error(errno, std::system_category());
}
}
ExternalCommitHelper::~ExternalCommitHelper()
{
REALM_ASSERT_DEBUG(m_realms.empty());
notify_fd(m_shutdown_write_fd);
pthread_join(m_thread, nullptr); // Wait for the thread to exit
}
void ExternalCommitHelper::add_realm(realm::Realm* realm)
{
std::lock_guard<std::mutex> lock(m_realms_mutex);
// Create the runloop source
CFRunLoopSourceContext ctx{};
ctx.info = realm;
ctx.perform = [](void* info) {
static_cast<Realm*>(info)->notify();
};
CFRunLoopRef runloop = CFRunLoopGetCurrent();
CFRetain(runloop);
CFRunLoopSourceRef signal = CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &ctx);
CFRunLoopAddSource(runloop, signal, kCFRunLoopDefaultMode);
m_realms.push_back({realm, runloop, signal});
}
void ExternalCommitHelper::remove_realm(realm::Realm* realm)
{
std::lock_guard<std::mutex> lock(m_realms_mutex);
for (auto it = m_realms.begin(); it != m_realms.end(); ++it) {
if (it->realm == realm) {
CFRunLoopSourceInvalidate(it->signal);
CFRelease(it->signal);
CFRelease(it->runloop);
m_realms.erase(it);
return;
}
}
REALM_TERMINATE("Realm not registered");
}
void ExternalCommitHelper::listen()
{
pthread_setname_np("RLMRealm notification listener");
// Set up the kqueue
// EVFILT_READ indicates that we care about data being available to read
// on the given file descriptor.
// EV_CLEAR makes it wait for the amount of data available to be read to
// change rather than just returning when there is any data to read.
struct kevent ke[2];
EV_SET(&ke[0], m_notify_fd, EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, 0);
EV_SET(&ke[1], m_shutdown_read_fd, EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, 0);
int ret = kevent(m_kq, ke, 2, nullptr, 0, nullptr);
assert(ret == 0);
while (true) {
struct kevent event;
// Wait for data to become on either fd
// Return code is number of bytes available or -1 on error
ret = kevent(m_kq, nullptr, 0, &event, 1, nullptr);
assert(ret >= 0);
if (ret == 0) {
// Spurious wakeup; just wait again
continue;
}
// Check which file descriptor had activity: if it's the shutdown
// pipe, then someone called -stop; otherwise it's the named pipe
// and someone committed a write transaction
if (event.ident == (uint32_t)m_shutdown_read_fd) {
return;
}
assert(event.ident == (uint32_t)m_notify_fd);
std::lock_guard<std::mutex> lock(m_realms_mutex);
for (auto const& realm : m_realms) {
CFRunLoopSourceSignal(realm.signal);
// Signalling the source makes it run the next time the runloop gets
// to it, but doesn't make the runloop start if it's currently idle
// waiting for events
CFRunLoopWakeUp(realm.runloop);
}
}
}
void ExternalCommitHelper::notify_others()
{
notify_fd(m_notify_fd);
}

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#ifndef REALM_EXTERNAL_COMMIT_HELPER_HPP
#define REALM_EXTERNAL_COMMIT_HELPER_HPP
#include <CoreFoundation/CFRunLoop.h>
#include <mutex>
#include <vector>
namespace realm {
class Realm;
class ExternalCommitHelper {
public:
ExternalCommitHelper(Realm* realm);
~ExternalCommitHelper();
void notify_others();
void add_realm(Realm* realm);
void remove_realm(Realm* realm);
private:
// A RAII holder for a file descriptor which automatically closes the wrapped
// fd when it's deallocated
class FdHolder {
public:
FdHolder() = default;
~FdHolder() { close(); }
operator int() const { return m_fd; }
FdHolder& operator=(int newFd) {
close();
m_fd = newFd;
return *this;
}
private:
int m_fd = -1;
void close();
FdHolder& operator=(FdHolder const&) = delete;
FdHolder(FdHolder const&) = delete;
};
struct PerRealmInfo {
Realm* realm;
CFRunLoopRef runloop;
CFRunLoopSourceRef signal;
};
void listen();
// Currently registered realms and the signal for delivering notifications
// to them
std::vector<PerRealmInfo> m_realms;
// Mutex which guards m_realms
std::mutex m_realms_mutex;
// The listener thread
pthread_t m_thread;
// Read-write file descriptor for the named pipe which is waited on for
// changes and written to when a commit is made
FdHolder m_notify_fd;
// File descriptor for the kqueue
FdHolder m_kq;
// The two ends of an anonymous pipe used to notify the kqueue() thread that
// it should be shut down.
FdHolder m_shutdown_read_fd;
FdHolder m_shutdown_write_fd;
};
} // namespace realm
#endif /* REALM_EXTERNAL_COMMIT_HELPER_HPP */

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#include "index_set.hpp"
using namespace realm;
IndexSet::iterator IndexSet::find(size_t index)
{
for (auto it = m_ranges.begin(), end = m_ranges.end(); it != end; ++it) {
if (it->second > index)
return it;
}
return m_ranges.end();
}
void IndexSet::add(size_t index)
{
do_add(find(index), index);
}
void IndexSet::do_add(iterator it, size_t index)
{
bool more_before = it != m_ranges.begin(), valid = it != m_ranges.end();
if (valid && it->first <= index && it->second > index) {
// index is already in set
}
else if (more_before && (it - 1)->second == index) {
// index is immediately after an existing range
++(it - 1)->second;
}
else if (more_before && valid && (it - 1)->second == it->first) {
// index joins two existing ranges
(it - 1)->second = it->second;
m_ranges.erase(it);
}
else if (valid && it->first == index + 1) {
// index is immediately before an existing range
--it->first;
}
else {
// index is not next to an existing range
m_ranges.insert(it, {index, index + 1});
}
}
void IndexSet::set(size_t len)
{
m_ranges.clear();
if (len) {
m_ranges.push_back({0, len});
}
}
void IndexSet::insert_at(size_t index)
{
auto pos = find(index);
if (pos != m_ranges.end()) {
if (pos->first >= index)
++pos->first;
++pos->second;
for (auto it = pos + 1; it != m_ranges.end(); ++it) {
++it->first;
++it->second;
}
}
do_add(pos, index);
}
void IndexSet::add_shifted(size_t index)
{
auto it = m_ranges.begin();
for (auto end = m_ranges.end(); it != end && it->first <= index; ++it) {
index += it->second - it->first;
}
do_add(it, index);
}

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#ifndef REALM_INDEX_SET_HPP
#define REALM_INDEX_SET_HPP
#include <vector>
namespace realm {
class IndexSet {
public:
using value_type = std::pair<size_t, size_t>;
using iterator = std::vector<value_type>::iterator;
using const_iterator = std::vector<value_type>::const_iterator;
const_iterator begin() const { return m_ranges.begin(); }
const_iterator end() const { return m_ranges.end(); }
bool empty() const { return m_ranges.empty(); }
size_t size() const { return m_ranges.size(); }
// Add an index to the set, doing nothing if it's already present
void add(size_t index);
// Remove all indexes from the set and then add a single range starting from
// zero with the given length
void set(size_t len);
// Insert an index at the given position, shifting existing indexes at or
// after that point back by one
void insert_at(size_t index);
// Add an index which has had all of the ranges in the set before it removed
void add_shifted(size_t index);
private:
std::vector<value_type> m_ranges;
// Find the range which contains the index, or the first one after it if
// none do
iterator find(size_t index);
// Insert the index before the given position, combining existing ranges as
// applicable
void do_add(iterator pos, size_t index);
};
} // namespace realm
#endif // REALM_INDEX_SET_HPP

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#ifndef REALM_OBJECT_STORE_HPP
#define REALM_OBJECT_STORE_HPP
#include "schema.hpp"
#include "object_schema.hpp"
#include "property.hpp"

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#ifndef REALM_DELEGATE_HPP
#define REALM_DELEGATE_HPP
#include "index_set.hpp"
#include <tuple>
#include <vector>
namespace realm {
// RealmDelegate is the extension point for adding binding-specific behavior to
// a SharedRealm. It can be used to store additonal data associated with the
// Realm which is needed by the binding, and there are several methods which
// can be overridden to receive notifications of state changes within the Realm.
//
// A simple delegate implementation which lets the user register functions to be
// called on refresh could look like the following:
//
// class DelegateImplementation : public RealmDelegate {
// public:
// // A token returned from add_notification that can be used to remove the
// // notification later
// struct token : private std::list<std::function<void ()>>::iterator {
// token(std::list<std::function<void ()>>::iterator it) : std::list<std::function<void ()>>::iterator(it) { }
// friend class DelegateImplementation;
// };
//
// token add_notification(std::function<void ()> func)
// {
// m_registered_notifications.push_back(std::move(func));
// return token(std::prev(m_registered_notifications.end()));
// }
//
// void remove_notification(token entry)
// {
// m_registered_notifications.erase(entry);
// }
//
// // Override the did_change method to call each registered notification
// void did_change(std::vector<ObserverState> const&, std::vector<void*> const&) override
// {
// // Loop oddly so that unregistering a notification from within the
// // registered function works
// for (auto it = m_registered_notifications.begin(); it != m_registered_notifications.end(); ) {
// (*it++)();
// }
// }
//
// private:
// std::list<std::function<void ()>> m_registered_notifications;
// };
class RealmDelegate {
public:
virtual ~RealmDelegate() = default;
// Called by the Realm when a write transaction is committed to the file by
// a different Realm instance (possibly in a different process)
virtual void changes_available() { }
struct ObserverState;
// Override this function if you want to recieve detailed information about
// external changes to a specific set of objects.
// This is called before each operation which may advance the read
// transaction to include
// ObserverStates for each row for which detailed change information is
// desired.
virtual std::vector<ObserverState> get_observed_rows() { return {}; }
// Called immediately before the read transaction is advanced if detailed
// change information was requested (by returning a non-empty array from
// get_observed_rows()).
// The observers vector is the vector returned by get_observed_row(),
// updated with change information. The invalidated vector is a list of the
// `info` fields of observed rows which will be deleted.
virtual void will_change(std::vector<ObserverState> const& observers,
std::vector<void*> const& invalidated);
// Called immediately after the read transaction version is advanced. Unlike
// will_change(), this is called even if detailed change information was not
// requested or if the Realm is not actually in a read transactuib, although
// both vectors will be empty in that case.
virtual void did_change(std::vector<ObserverState> const& observers,
std::vector<void*> const& invalidated);
// Change information for a single field of a row
struct ColumnInfo {
// Did this column change?
bool changed = false;
// For LinkList columns, what kind of change occurred?
// Always None for other column types
enum class Kind {
None, // No change
Set, // The entries at `indices` were assigned to
Insert, // New values were inserted at each of the indices given
Remove, // Values were removed at each of the indices given
SetAll // The entire LinkList has been replaced with a new set of values
} kind = Kind::None;
// The indices where things happened for Set, Insert and Remove
// Not used for None and SetAll
IndexSet indices;
};
// Information about an observed row in a table
//
// Each object which needs detailed change information should have an
// ObserverState entry in the vector returned from get_observed_rows(), with
// the initial table and row indexes set (and optionally the info field).
// The Realm parses the transaction log, and populates the `changes` vector
// in each ObserverState with information about what changes were made.
struct ObserverState {
// Initial table and row which is observed
// May be updated by row insertions and removals
size_t table_ndx;
size_t row_ndx;
// Opaque userdata for the delegate's use
void* info;
// Populated with information about which columns were changed
// May be shorter than the actual number of columns if the later columns
// are not modified
std::vector<ColumnInfo> changes;
// Simple lexographic ordering
friend bool operator<(ObserverState const& lft, ObserverState const& rgt)
{
return std::tie(lft.table_ndx, lft.row_ndx) < std::tie(rgt.table_ndx, rgt.row_ndx);
}
};
};
inline void RealmDelegate::will_change(std::vector<ObserverState> const&, std::vector<void*> const&) { }
inline void RealmDelegate::did_change(std::vector<ObserverState> const&, std::vector<void*> const&) { }
} // namespace realm
#endif /* REALM_DELEGATE_HPP */

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#include "schema.hpp"
#include "object_schema.hpp"
#include "object_store.hpp"
#include "property.hpp"
using namespace realm;
static bool compare_by_name(ObjectSchema const& lft, ObjectSchema const& rgt) {
return lft.name < rgt.name;
}
Schema::Schema(base types) : base(std::move(types)) {
std::sort(begin(), end(), compare_by_name);
}
Schema::iterator Schema::find(std::string const& name)
{
ObjectSchema cmp;
cmp.name = name;
return find(cmp);
}
Schema::const_iterator Schema::find(std::string const& name) const
{
return const_cast<Schema *>(this)->find(name);
}
Schema::iterator Schema::find(ObjectSchema const& object) noexcept
{
auto it = std::lower_bound(begin(), end(), object, compare_by_name);
if (it != end() && it->name != object.name) {
it = end();
}
return it;
}
Schema::const_iterator Schema::find(ObjectSchema const& object) const noexcept
{
return const_cast<Schema *>(this)->find(object);
}
void Schema::validate() const
{
std::vector<ObjectSchemaValidationException> exceptions;
for (auto const& object : *this) {
const Property *primary = nullptr;
for (auto const& prop : object.properties) {
// check object_type existence
if (!prop.object_type.empty() && find(prop.object_type) == end()) {
exceptions.emplace_back(MissingObjectTypeException(object.name, prop));
}
// check nullablity
if (prop.is_nullable) {
#if REALM_NULL_STRINGS == 1
if (prop.type == PropertyTypeArray || prop.type == PropertyTypeAny) {
#else
if (prop.type != PropertyTypeObject) {
#endif
exceptions.emplace_back(InvalidNullabilityException(object.name, prop));
}
}
else if (prop.type == PropertyTypeObject) {
exceptions.emplace_back(InvalidNullabilityException(object.name, prop));
}
// check primary keys
if (prop.is_primary) {
if (primary) {
exceptions.emplace_back(DuplicatePrimaryKeysException(object.name));
}
primary = &prop;
}
// check indexable
if (prop.is_indexed) {
if (prop.type != PropertyTypeString && prop.type != PropertyTypeInt) {
exceptions.emplace_back(PropertyTypeNotIndexableException(object.name, prop));
}
}
}
}
if (exceptions.size()) {
throw SchemaValidationException(exceptions);
}
}

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#ifndef REALM_SCHEMA_HPP
#define REALM_SCHEMA_HPP
#include <vector>
namespace realm {
class ObjectSchema;
class Schema : private std::vector<ObjectSchema> {
private:
using base = std::vector<ObjectSchema>;
public:
// Create a schema from a vector of ObjectSchema
Schema(base types);
// find an ObjectSchema by name
iterator find(std::string const& name);
const_iterator find(std::string const& name) const;
// find an ObjectSchema with the same name as the passed in one
iterator find(ObjectSchema const& object) noexcept;
const_iterator find(ObjectSchema const& object) const noexcept;
// Verify that this schema is internally consistent (i.e. all properties are
// valid, links link to types that actually exist, etc.)
void validate() const;
using base::iterator;
using base::const_iterator;
using base::begin;
using base::end;
using base::empty;
using base::size;
};
}
#endif /* defined(REALM_SCHEMA_HPP) */

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#include "transact_log_handler.hpp"
#include "realm_delegate.hpp"
#include <realm/commit_log.hpp>
#include <realm/group_shared.hpp>
#include <realm/lang_bind_helper.hpp>
using namespace realm;
namespace {
class TransactLogHandler {
using ColumnInfo = RealmDelegate::ColumnInfo;
using ObserverState = RealmDelegate::ObserverState;
// Observed table rows which need change information
std::vector<ObserverState> m_observers;
// Userdata pointers for rows which have been deleted
std::vector<void *> invalidated;
// Delegate to send change information to
RealmDelegate* m_delegate;
// Index of currently selected table
size_t m_current_table = 0;
// Change information for the currently selected LinkList, if any
ColumnInfo* m_active_linklist = nullptr;
// Get the change info for the given column, creating it if needed
static ColumnInfo& get_change(ObserverState& state, size_t i)
{
if (state.changes.size() <= i) {
state.changes.resize(std::max(state.changes.size() * 2, i + 1));
}
return state.changes[i];
}
// Loop over the columns which were changed in an observer state
template<typename Func>
static void for_each(ObserverState& state, Func&& f)
{
for (size_t i = 0; i < state.changes.size(); ++i) {
auto const& change = state.changes[i];
if (change.changed) {
f(i, change);
}
}
}
// Mark the given row/col as needing notifications sent
bool mark_dirty(size_t row_ndx, size_t col_ndx)
{
auto it = lower_bound(begin(m_observers), end(m_observers), ObserverState{m_current_table, row_ndx, nullptr});
if (it != end(m_observers) && it->table_ndx == m_current_table && it->row_ndx == row_ndx) {
get_change(*it, col_ndx).changed = true;
}
return true;
}
// Remove the given observer from the list of observed objects and add it
// to the listed of invalidated objects
void invalidate(ObserverState *o)
{
invalidated.push_back(o->info);
m_observers.erase(m_observers.begin() + (o - &m_observers[0]));
}
public:
template<typename Func>
TransactLogHandler(RealmDelegate* delegate, SharedGroup& sg, Func&& func)
: m_delegate(delegate)
{
if (!delegate) {
func();
return;
}
m_observers = delegate->get_observed_rows();
if (m_observers.empty()) {
auto old_version = sg.get_version_of_current_transaction();
func();
if (old_version != sg.get_version_of_current_transaction()) {
delegate->did_change({}, {});
}
return;
}
func(*this);
delegate->did_change(m_observers, invalidated);
}
// Called at the end of the transaction log immediately before the version
// is advanced
void parse_complete()
{
m_delegate->will_change(m_observers, invalidated);
}
// These would require having an observer before schema init
// Maybe do something here to throw an error when multiple processes have different schemas?
bool insert_group_level_table(size_t, size_t, StringData) { return false; }
bool erase_group_level_table(size_t, size_t) { return false; }
bool rename_group_level_table(size_t, StringData) { return false; }
bool insert_column(size_t, DataType, StringData, bool) { return false; }
bool insert_link_column(size_t, DataType, StringData, size_t, size_t) { return false; }
bool erase_column(size_t) { return false; }
bool erase_link_column(size_t, size_t, size_t) { return false; }
bool rename_column(size_t, StringData) { return false; }
bool add_search_index(size_t) { return false; }
bool remove_search_index(size_t) { return false; }
bool add_primary_key(size_t) { return false; }
bool remove_primary_key() { return false; }
bool set_link_type(size_t, LinkType) { return false; }
bool select_table(size_t group_level_ndx, int, const size_t*) noexcept
{
m_current_table = group_level_ndx;
return true;
}
bool insert_empty_rows(size_t, size_t, size_t, bool)
{
// rows are only inserted at the end, so no need to do anything
return true;
}
bool erase_rows(size_t row_ndx, size_t, size_t last_row_ndx, bool unordered)
{
for (size_t i = 0; i < m_observers.size(); ++i) {
auto& o = m_observers[i];
if (o.table_ndx == m_current_table) {
if (o.row_ndx == row_ndx) {
invalidate(&o);
--i;
}
else if (unordered && o.row_ndx == last_row_ndx) {
o.row_ndx = row_ndx;
}
else if (!unordered && o.row_ndx > row_ndx) {
o.row_ndx -= 1;
}
}
}
return true;
}
bool clear_table()
{
for (size_t i = 0; i < m_observers.size(); ) {
auto& o = m_observers[i];
if (o.table_ndx == m_current_table) {
invalidate(&o);
}
else {
++i;
}
}
return true;
}
bool select_link_list(size_t col, size_t row)
{
m_active_linklist = nullptr;
for (auto& o : m_observers) {
if (o.table_ndx == m_current_table && o.row_ndx == row) {
m_active_linklist = &get_change(o, col);
break;
}
}
return true;
}
void append_link_list_change(ColumnInfo::Kind kind, size_t index) {
ColumnInfo *o = m_active_linklist;
if (!o || o->kind == ColumnInfo::Kind::SetAll) {
// Active LinkList isn't observed or already has multiple kinds of changes
return;
}
if (o->kind == ColumnInfo::Kind::None) {
o->kind = kind;
o->changed = true;
o->indices.add(index);
}
else if (o->kind == kind) {
if (kind == ColumnInfo::Kind::Remove) {
o->indices.add_shifted(index);
}
else if (kind == ColumnInfo::Kind::Insert) {
o->indices.insert_at(index);
}
else {
o->indices.add(index);
}
}
else {
// Array KVO can only send a single kind of change at a time, so
// if there's multiple just give up and send "Set"
o->indices.set(0);
o->kind = ColumnInfo::Kind::SetAll;
}
}
bool link_list_set(size_t index, size_t)
{
append_link_list_change(ColumnInfo::Kind::Set, index);
return true;
}
bool link_list_insert(size_t index, size_t)
{
append_link_list_change(ColumnInfo::Kind::Insert, index);
return true;
}
bool link_list_erase(size_t index)
{
append_link_list_change(ColumnInfo::Kind::Remove, index);
return true;
}
bool link_list_nullify(size_t index)
{
append_link_list_change(ColumnInfo::Kind::Remove, index);
return true;
}
bool link_list_swap(size_t index1, size_t index2)
{
append_link_list_change(ColumnInfo::Kind::Set, index1);
append_link_list_change(ColumnInfo::Kind::Set, index2);
return true;
}
bool link_list_clear(size_t old_size)
{
ColumnInfo *o = m_active_linklist;
if (!o || o->kind == ColumnInfo::Kind::SetAll) {
return true;
}
if (o->kind == ColumnInfo::Kind::Remove)
old_size += o->indices.size();
else if (o->kind == ColumnInfo::Kind::Insert)
old_size -= o->indices.size();
o->indices.set(old_size);
o->kind = ColumnInfo::Kind::Remove;
o->changed = true;
return true;
}
bool link_list_move(size_t from, size_t to)
{
ColumnInfo *o = m_active_linklist;
if (!o || o->kind == ColumnInfo::Kind::SetAll) {
return true;
}
if (from > to) {
std::swap(from, to);
}
if (o->kind == ColumnInfo::Kind::None) {
o->kind = ColumnInfo::Kind::Set;
o->changed = true;
}
if (o->kind == ColumnInfo::Kind::Set) {
for (size_t i = from; i <= to; ++i)
o->indices.add(i);
}
else {
o->indices.set(0);
o->kind = ColumnInfo::Kind::SetAll;
}
return true;
}
// Things that just mark the field as modified
bool set_int(size_t col, size_t row, int_fast64_t) { return mark_dirty(row, col); }
bool set_bool(size_t col, size_t row, bool) { return mark_dirty(row, col); }
bool set_float(size_t col, size_t row, float) { return mark_dirty(row, col); }
bool set_double(size_t col, size_t row, double) { return mark_dirty(row, col); }
bool set_string(size_t col, size_t row, StringData) { return mark_dirty(row, col); }
bool set_binary(size_t col, size_t row, BinaryData) { return mark_dirty(row, col); }
bool set_date_time(size_t col, size_t row, DateTime) { return mark_dirty(row, col); }
bool set_table(size_t col, size_t row) { return mark_dirty(row, col); }
bool set_mixed(size_t col, size_t row, const Mixed&) { return mark_dirty(row, col); }
bool set_link(size_t col, size_t row, size_t) { return mark_dirty(row, col); }
bool set_null(size_t col, size_t row) { return mark_dirty(row, col); }
bool nullify_link(size_t col, size_t row) { return mark_dirty(row, col); }
// Doesn't change any data
bool optimize_table() { return true; }
// Used for subtables, which we currently don't support
bool select_descriptor(int, const size_t*) { return false; }
};
} // anonymous namespace
namespace realm {
namespace transaction {
void advance(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate) {
TransactLogHandler(delegate, sg, [&](auto&&... args) {
LangBindHelper::advance_read(sg, history, std::move(args)...);
});
}
void begin(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate) {
TransactLogHandler(delegate, sg, [&](auto&&... args) {
LangBindHelper::promote_to_write(sg, history, std::move(args)...);
});
}
void commit(SharedGroup& sg, ClientHistory&, RealmDelegate* delegate) {
LangBindHelper::commit_and_continue_as_read(sg);
if (delegate) {
delegate->did_change({}, {});
}
}
void cancel(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate) {
TransactLogHandler(delegate, sg, [&](auto&&... args) {
LangBindHelper::rollback_and_continue_as_read(sg, history, std::move(args)...);
});
}
} // namespace transaction
} // namespace realm

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////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#ifndef REALM_TRANSACT_LOG_HANDLER_HPP
#define REALM_TRANSACT_LOG_HANDLER_HPP
namespace realm {
class RealmDelegate;
class SharedGroup;
class ClientHistory;
namespace transaction {
// Advance the read transaction version, with change notifications sent to delegate
// Must not be called from within a write transaction.
void advance(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate);
// Begin a write transaction
// If the read transaction version is not up to date, will first advance to the
// most recent read transaction and sent notifications to delegate
void begin(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate);
// Commit a write transaction
void commit(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate);
// Cancel a write transaction and roll back all changes, with change notifications
// for reverting to the old values sent to delegate
void cancel(SharedGroup& sg, ClientHistory& history, RealmDelegate* delegate);
} // namespace transaction
} // namespace realm
#endif /* REALM_TRANSACT_LOG_HANDLER_HPP */