From f8811bbd3a40df5962cf6f6274802a7cfd229f2e Mon Sep 17 00:00:00 2001
From: Tao Bao <tbao@google.com>
Date: Mon, 18 Jun 2018 10:03:52 -0700
Subject: updater: Add TransferList class.

This would be the top-level class that represents and holds the info
parsed from a transfer list file.

Bug: 112151972
Test: Run recovery_unit_test and recovery_component_test on marlin.
Change-Id: I83b54df9d1411542eeeb8ef4a2db167e97f989c3
---
 updater/include/private/commands.h | 67 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

(limited to 'updater/include/private/commands.h')

diff --git a/updater/include/private/commands.h b/updater/include/private/commands.h
index 521289780..79f915434 100644
--- a/updater/include/private/commands.h
+++ b/updater/include/private/commands.h
@@ -406,3 +406,70 @@ class Command {
 };
 
 std::ostream& operator<<(std::ostream& os, const Command& command);
+
+// TransferList represents the info for a transfer list, which is parsed from input text lines
+// containing commands to transfer data from one place to another on the target partition.
+//
+// The creator of the transfer list will guarantee that no block is read (i.e., used as the source
+// for a patch or move) after it has been written.
+//
+// The creator will guarantee that a given stash is loaded (with a stash command) before it's used
+// in a move/bsdiff/imgdiff command.
+//
+// Within one command the source and target ranges may overlap so in general we need to read the
+// entire source into memory before writing anything to the target blocks.
+//
+// All the patch data is concatenated into one patch_data file in the update package. It must be
+// stored uncompressed because we memory-map it in directly from the archive. (Since patches are
+// already compressed, we lose very little by not compressing their concatenation.)
+//
+// Commands that read data from the partition (i.e. move/bsdiff/imgdiff/stash) have one or more
+// additional hashes before the range parameters, which are used to check if the command has
+// already been completed and verify the integrity of the source data.
+class TransferList {
+ public:
+  // Number of header lines.
+  static constexpr size_t kTransferListHeaderLines = 4;
+
+  TransferList() = default;
+
+  // Parses the given input string and returns a TransferList object. Sets error message if any.
+  static TransferList Parse(const std::string& transfer_list_str, std::string* err);
+
+  int version() const {
+    return version_;
+  }
+
+  size_t total_blocks() const {
+    return total_blocks_;
+  }
+
+  size_t stash_max_entries() const {
+    return stash_max_entries_;
+  }
+
+  size_t stash_max_blocks() const {
+    return stash_max_blocks_;
+  }
+
+  const std::vector<Command>& commands() const {
+    return commands_;
+  }
+
+  // Returns whether the TransferList is valid.
+  constexpr explicit operator bool() const {
+    return version_ != 0;
+  }
+
+ private:
+  // BBOTA version.
+  int version_{ 0 };
+  // Total number of blocks to be written in this transfer.
+  size_t total_blocks_;
+  // Maximum number of stashes that exist at the same time.
+  size_t stash_max_entries_;
+  // Maximum number of blocks to be stashed.
+  size_t stash_max_blocks_;
+  // Commands in this transfer.
+  std::vector<Command> commands_;
+};
-- 
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