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content / browser / code_cache / generated_code_cache.h [blame]
// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_CODE_CACHE_GENERATED_CODE_CACHE_H_
#define CONTENT_BROWSER_CODE_CACHE_GENERATED_CODE_CACHE_H_
#include <map>
#include <queue>
#include "base/containers/queue.h"
#include "base/files/file_path.h"
#include "base/memory/weak_ptr.h"
#include "base/timer/timer.h"
#include "content/browser/code_cache/simple_lru_cache.h"
#include "content/common/content_export.h"
#include "mojo/public/cpp/base/big_buffer.h"
#include "net/base/io_buffer.h"
#include "net/base/network_isolation_key.h"
#include "net/disk_cache/disk_cache.h"
#include "url/origin.h"
namespace content {
// Cache for storing generated code from the renderer on the disk. This cache
// uses |resource_url| + |origin_lock| as a key for storing the generated code.
// |resource_url| is the url corresponding to the requested resource.
// |origin_lock| is the origin that the renderer which requested this resource
// is locked to. This is used to enforce site isolation policy on cached code.
// For example, if SitePerProcess is enabled and http://script.com/script1.js is
// requested by http://example.com, then http://script.com/script.js is the
// resource_url and http://example.com is the origin_lock.
//
// The key is generated by concatenating the serialized url and origin lock
// with a separator in between. The separator is non-valid URL characters, to
// prevent any attacks by crafting the URLs. |origin_lock| could be empty when
// renderer is not locked to an origin (ex:SitePerProcess is disabled) and it
// is safe to use only |resource_url| as the key in such cases.
//
// This uses a simple disk_cache backend. It just stores one data stream and
// stores response_time + generated code as one data blob.
//
// There exists one cache per storage partition and is owned by the storage
// partition. This cache is created, accessed and destroyed on the I/O
// thread.
class CONTENT_EXPORT GeneratedCodeCache {
public:
using ReadDataCallback =
base::OnceCallback<void(const base::Time&, mojo_base::BigBuffer data)>;
using GetBackendCallback = base::OnceCallback<void(disk_cache::Backend*)>;
// Cache type. Used for collecting statistics for JS and Wasm in separate
// buckets.
enum CodeCacheType {
// JavaScript from http(s) pages.
kJavaScript,
// WebAssembly from http(s) pages. This cache allows more total size and
// more size per item than the JavaScript cache, since some
// WebAssembly programs are very large.
kWebAssembly,
// JavaScript from chrome and chrome-untrusted pages. The resource URLs are
// limited to only those fetched via chrome and chrome-untrusted schemes.
// The cache size is limited to disk_cache::kMaxWebUICodeCacheSize.
// Deduplication of very large items is disabled in this cache.
kWebUIJavaScript,
};
// Used for collecting statistics about cache behaviour.
// Since it's uploaded to UMA, its values must never change.
enum CacheEntryStatus : uint8_t {
kHit,
kMiss,
kClear,
kUpdate,
kCreate,
kError,
kIncompleteEntry,
kWriteFailed,
kMaxValue = kWriteFailed
};
// Returns the resource URL from the key. The key has the format prefix +
// resource URL + separator + requesting origin. This function extracts and
// returns resource URL from the key, or the empty string if key is invalid.
static std::string GetResourceURLFromKey(const std::string& key);
// Creates a GeneratedCodeCache with the specified path and the maximum size.
// If |max_size_bytes| is 0, then disk_cache picks a default size based on
// some heuristics.
GeneratedCodeCache(const base::FilePath& path,
int max_size_bytes,
CodeCacheType cache_type);
GeneratedCodeCache(const GeneratedCodeCache&) = delete;
GeneratedCodeCache& operator=(const GeneratedCodeCache&) = delete;
~GeneratedCodeCache();
// Runs the callback with a raw pointer to the backend. If we could not create
// the backend then it will return a null. This runs the callback
// synchronously if the backend is already open or asynchronously on the
// completion of a pending backend creation.
void GetBackend(GetBackendCallback callback);
// Writes data to the cache. If there is an entry corresponding to
// <|resource_url|, |origin_lock|> this overwrites the existing data. If
// there is no entry it creates a new one.
void WriteEntry(const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
const base::Time& response_time,
mojo_base::BigBuffer data);
// Fetch entry corresponding to <resource_url, origin_lock> from the cache
// and return it using the ReadDataCallback.
void FetchEntry(const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
ReadDataCallback);
// Delete the entry corresponding to <resource_url, origin_lock>
void DeleteEntry(const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik);
// Should be only used for tests. Sets the last accessed timestamp of an
// entry.
void SetLastUsedTimeForTest(const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
base::Time time,
base::OnceClosure callback);
// Clears the in-memory cache.
void ClearInMemoryCache();
void CollectStatisticsForTest(const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CacheEntryStatus status);
const base::FilePath& path() const { return path_; }
private:
class PendingOperation;
// State of the backend.
enum BackendState { kInitializing, kInitialized, kFailed };
// The operation requested.
enum Operation {
kFetch,
kFetchWithSHAKey,
kWrite,
kWriteWithSHAKey,
kDelete,
kGetBackend
};
// Data streams corresponding to each entry.
enum { kSmallDataStream = 0, kLargeDataStream = 1 };
// Creates a simple_disk_cache backend.
void CreateBackend();
void DidCreateBackend(disk_cache::BackendResult result);
// Adds operation to the appropriate queue.
void EnqueueOperation(std::unique_ptr<PendingOperation> op);
// Issues ops that were received while the backend was being initialized.
void IssuePendingOperations();
void IssueOperation(PendingOperation* op);
// Writes entry to cache.
void WriteEntryImpl(PendingOperation* op);
void OpenCompleteForWrite(PendingOperation* op,
disk_cache::EntryResult result);
void WriteSmallBufferComplete(PendingOperation* op, int rv);
void WriteLargeBufferComplete(PendingOperation* op, int rv);
void WriteComplete(PendingOperation* op);
// Fetches entry from cache.
void FetchEntryImpl(PendingOperation* op);
void OpenCompleteForRead(PendingOperation* op,
disk_cache::EntryResult result);
void ReadSmallBufferComplete(PendingOperation* op, int rv);
void ReadLargeBufferComplete(PendingOperation* op, int rv);
void ReadComplete(PendingOperation* op);
// Deletes entry from cache.
void DeleteEntryImpl(PendingOperation* op);
void DoomEntry(PendingOperation* op);
// Issues the next operation on the queue for |key|.
void IssueNextOperation(const std::string& key);
// Removes |op| and issues the next operation on its queue.
void CloseOperationAndIssueNext(PendingOperation* op);
// Enqueues the operation issues it if there are no pending operations for
// its key.
void EnqueueOperationAndIssueIfNext(std::unique_ptr<PendingOperation> op);
// Dequeues the operation and transfers ownership to caller.
std::unique_ptr<PendingOperation> DequeueOperation(PendingOperation* op);
void DoPendingGetBackend(PendingOperation* op);
void OpenCompleteForSetLastUsedForTest(base::Time time,
base::OnceClosure callback,
disk_cache::EntryResult result);
void CollectStatistics(const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CacheEntryStatus status);
// Whether very large cache entries are deduplicated in this cache.
// Deduplication is disabled in the WebUI code cache, as an additional defense
// against privilege escalation in case there is a bug in the deduplication
// logic.
bool IsDeduplicationEnabled() const;
bool ShouldDeduplicateEntry(uint32_t data_size) const;
// Checks that the header data in the small buffer is valid. We may read cache
// entries that were written by a previous version of Chrome which uses
// obsolete formats. These reads should fail and be doomed as soon as
// possible.
bool IsValidHeader(scoped_refptr<net::IOBufferWithSize> small_buffer) const;
void ReportPeriodicalHistograms();
std::unique_ptr<disk_cache::Backend> backend_;
BackendState backend_state_;
// Queue for operations received while initializing the backend.
using PendingOperationQueue = base::queue<std::unique_ptr<PendingOperation>>;
PendingOperationQueue pending_ops_;
// Map from key to queue of pending operations.
std::map<std::string, PendingOperationQueue> active_entries_map_;
base::FilePath path_;
int max_size_bytes_;
CodeCacheType cache_type_;
// A hypothetical memory-backed code cache. Used to collect UMAs.
SimpleLruCache lru_cache_;
base::RepeatingTimer histograms_timer_;
static constexpr int64_t kLruCacheCapacity = 50 * 1024 * 1024;
base::WeakPtrFactory<GeneratedCodeCache> weak_ptr_factory_{this};
};
} // namespace content
#endif // CONTENT_BROWSER_CODE_CACHE_GENERATED_CODE_CACHE_H_