OLD | NEW |
(Empty) | |
| 1 // Copyright 2016 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #ifndef CHROMEOS_PRINTING_PPD_CACHE_H_ |
| 6 #define CHROMEOS_PRINTING_PPD_CACHE_H_ |
| 7 |
| 8 #include <memory> |
| 9 #include <string> |
| 10 |
| 11 #include "base/files/file_path.h" |
| 12 #include "base/optional.h" |
| 13 #include "chromeos/chromeos_export.h" |
| 14 #include "chromeos/printing/printer_configuration.h" |
| 15 |
| 16 namespace chromeos { |
| 17 namespace printing { |
| 18 |
| 19 // PpdCache manages a cache of locally-stored PPD files. At its core, it |
| 20 // operates like a persistent hash from PpdReference to files. If you give the |
| 21 // same PpdReference to Find() that was previously given to store, you should |
| 22 // get the same FilePath back out (unless the previous entry has timed out of |
| 23 // the cache). However, changing *any* field in PpdReference will make the |
| 24 // previous cache entry invalid. This is the intentional behavior -- we want to |
| 25 // re-run the resolution logic if we have new meta-information about a printer. |
| 26 class CHROMEOS_EXPORT PpdCache { |
| 27 public: |
| 28 // Create and return a Ppdcache that uses cache_dir to store state. |
| 29 static std::unique_ptr<PpdCache> Create(const base::FilePath& cache_base_dir); |
| 30 virtual ~PpdCache() {} |
| 31 |
| 32 // Find a PPD that was previously cached with the given reference. Note that |
| 33 // all fields of the reference must be the same, otherwise we'll miss in the |
| 34 // cache and re-run resolution for the PPD. |
| 35 // |
| 36 // If a FilePath is returned, it is guaranteed to be non-empty and |
| 37 // remain valid until the next Store() call. |
| 38 virtual base::Optional<base::FilePath> Find( |
| 39 const Printer::PpdReference& reference) const = 0; |
| 40 |
| 41 // Take the contents of a PPD file, store it to the cache, and return the |
| 42 // path to the stored file keyed on reference. |
| 43 // |
| 44 // If a different PPD was previously Stored for the given reference, it |
| 45 // will be replaced. |
| 46 // |
| 47 // If a FilePath is returned, it is guaranteed to be non-empty and |
| 48 // remain valid until the next Store() call. |
| 49 virtual base::Optional<base::FilePath> Store( |
| 50 const Printer::PpdReference& reference, |
| 51 const std::string& ppd_contents) = 0; |
| 52 }; |
| 53 |
| 54 } // namespace printing |
| 55 } // namespace chromeos |
| 56 |
| 57 #endif // CHROMEOS_PRINTING_PPD_CACHE_H_ |
OLD | NEW |