diff options
Diffstat (limited to 'applypatch/include/applypatch/applypatch.h')
| -rw-r--r-- | applypatch/include/applypatch/applypatch.h | 58 |
1 files changed, 48 insertions, 10 deletions
diff --git a/applypatch/include/applypatch/applypatch.h b/applypatch/include/applypatch/applypatch.h index 77125f9de..ef133f290 100644 --- a/applypatch/include/applypatch/applypatch.h +++ b/applypatch/include/applypatch/applypatch.h @@ -39,23 +39,61 @@ using SinkFn = std::function<size_t(const unsigned char*, size_t)>; // applypatch.cpp int ShowLicenses(); + +// Returns the amount of free space (in bytes) on the filesystem containing filename, or -1 on +// error. filename must exist. size_t FreeSpaceForFile(const std::string& filename); + +// Checks whether /cache partition has at least 'bytes'-byte free space. Returns 0 on having +// sufficient space. int CacheSizeCheck(size_t bytes); + +// Parses a given string of 40 hex digits into 20-byte array 'digest'. 'str' may contain only the +// digest or be of the form "<digest>:<anything>". Returns 0 on success, or -1 on any error. int ParseSha1(const char* str, uint8_t* digest); -int applypatch(const char* source_filename, - const char* target_filename, - const char* target_sha1_str, - size_t target_size, - const std::vector<std::string>& patch_sha1_str, - const std::vector<std::unique_ptr<Value>>& patch_data, - const Value* bonus_data); -int applypatch_check(const char* filename, - const std::vector<std::string>& patch_sha1_str); +// Applies binary patches to eMMC target files in a way that is safe (the original file is not +// touched until we have the desired replacement for it) and idempotent (it's okay to run this +// program multiple times). +// +// - If the SHA-1 hash of 'target_filename' is 'target_sha1_string', does nothing and returns +// successfully. +// +// - Otherwise, if the SHA-1 hash of 'source_filename' is one of the entries in 'patch_sha1s', the +// corresponding patch from 'patch_data' (which must be a VAL_BLOB) is applied to produce a new +// file (the type of patch is automatically detected from the blob data). If that new file has +// SHA-1 hash 'target_sha1_str', moves it to replace 'target_filename', and exits successfully. +// Note that if 'source_filename' and 'target_filename' are not the same, 'source_filename' is +// NOT deleted on success. 'target_filename' may be the string "-" to mean +// "the same as 'source_filename'". +// +// - Otherwise, or if any error is encountered, exits with non-zero status. +// +// 'source_filename' must refer to an eMMC partition to read the source data. See the comments for +// the LoadPartitionContents() function for the format of such a filename. 'target_size' has become +// obsolete since we have dropped the support for patching non-eMMC targets (eMMC targets have the +// size embedded in the filename). +int applypatch(const char* source_filename, const char* target_filename, + const char* target_sha1_str, size_t target_size, + const std::vector<std::string>& patch_sha1s, + const std::vector<std::unique_ptr<Value>>& patch_data, const Value* bonus_data); + +// Returns 0 if the contents of the file or the cached file match any of the given SHA-1's. Returns +// nonzero otherwise. +int applypatch_check(const char* filename, const std::vector<std::string>& patch_sha1s); + +// Flashes a given image to the target partition. It verifies the target cheksum first, and will +// return if target already has the desired hash. Otherwise it checks the checksum of the given +// source image before flashing, and verifies the target partition afterwards. The function is +// idempotent. Returns zero on success. int applypatch_flash(const char* source_filename, const char* target_filename, const char* target_sha1_str, size_t target_size); +// Reads a file into memory; stores the file contents and associated metadata in *file. Returns 0 +// on success, or -1 on error. int LoadFileContents(const char* filename, FileContents* file); + +// Saves the given FileContents object to the given filename. Returns 0 on success, or -1 on error. int SaveFileContents(const char* filename, const FileContents* file); // bspatch.cpp @@ -79,9 +117,9 @@ int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value& // freecache.cpp int MakeFreeSpaceOnCache(size_t bytes_needed); + // Removes the files in |dirname| until we have at least |bytes_needed| bytes of free space on // the partition. The size of the free space is returned by calling |space_checker|. bool RemoveFilesInDirectory(size_t bytes_needed, const std::string& dirname, const std::function<size_t(const std::string&)>& space_checker); - #endif |