How To Patch An Application In Emulator/device Similar To How Google Play Is Doing With "Smart App Updates"?

Is it possible to achieve locally (using adb or other ways) what Google Play is doing in 'Smart app updates' ? What I want to do is to create a binary diff on the PC (using some co

Solution 1:

I would say that between the usage print out:

usage: applypatch [-b <bonus-file>] <src-file> <tgt-file> <tgt-sha1> <tgt-size> [<src-sha1>:<patch> ...]
   or  applypatch -c <file> [<sha1> ...]
   or  applypatch -s <bytes>
   or  applypatch -l

Filenames may be of the form
  MTD:<partition>:<len_1>:<sha1_1>:<len_2>:<sha1_2>:...
to specify reading from or writing to an MTD partition.

and the comments below:

// This program applies binary patches to 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 sha1 hash of <tgt-file> is <tgt-sha1>, does nothing and exits
//   successfully.
//
// - otherwise, if no <src-sha1>:<patch> is provided, flashes <tgt-file> with
//   <src-file>. <tgt-file> must be a partition name, while <src-file> must
//   be a regular image file. <src-file> will not be deleted on success.
//
// - otherwise, if the sha1 hash of <src-file> is <src-sha1>, applies the
//   bsdiff <patch> to <src-file> to produce a new file (the type of patch
//   is automatically detected from the file header).  If that new
//   file has sha1 hash <tgt-sha1>, moves it to replace <tgt-file>, and
//   exits successfully.  Note that if <src-file> and <tgt-file> are
//   not the same, <src-file> is NOT deleted on success.  <tgt-file>
//   may be the string "-" to mean "the same as src-file".
//
// - otherwise, or if any error is encountered, exits with non-zero
//   status.
//
// <src-file> (or <file> in check mode) may refer to an EMMC partition
// to read the source data.  See the comments for the
// LoadPartitionContents() function for the format of such a filename.

it is pretty straight-forward.

So the basic command to patch com.appv1.apk with diff.bin and save the result to the com.appv2.apk would be:

applypatch com.appv1.apk com.appv2.apk <com.appv2.apk SHA1> <com.appv2.apk size> <com.appv1.apk SHA1>:diff.bin