zkevm

README

zkEVM DataStreamer

Binary file format

Header page

The first page is the header.
Header page size = 4096 bytes

Magic numbers

At the beginning of the file there are the following magic bytes (file signature): polygonDATSTREAM

Header entry format (HeaderEntry struct)

u8 packetType = 1 // 1:Header
u32 headerLength = 29 // Total length of header entry
u64 streamType // 1:Sequencer
u64 totalLength // Total bytes used in the file
u64 totalEntries // Total number of data entries

Data page

From the second page starts the data pages.
Page size = 1 MB

Data entry format (FileEntry struct)

u8 packetType // 2:Data entry, 0:Padding
u32 length // Total length of data entry (17 bytes + length(data))
u32 entryType // 0xb0:Bookmark, 1:Event1, 2:Event2,...
u64 entryNumber // Entry number (sequential starting with 0)
u8[] data

If an entry do not fits in the remaining page space we store this entry in the next page.

Diagram

TCP/IP Commands

All the commands available for stream clients returns a result.
Some commands like start may return more data.

Start

Syncs from entry number (fromEntryNumber) and starts receiving data streaming.

u64 command = 1
u64 streamType // 1:Sequencer
u64 fromEntryNumber

StartBookmark

Syncs from bookmark (fromBookmark) and starts receiving data streaming.

u64 command = 4
u64 streamType // 1:Sequencer
u32 bookmarkLength // Length of fromBookmark
u8[] fromBookmark

After either start command, the system start stream data from that entry number or bookmark.

If already started terminate connection.

Stop

u64 command = 2
u64 streamType // 1:Sequencer

Stop streaming data.

If not started terminate connection.

The result is sended just after it's stopped.

Header

u64 command = 3
u64 streamType // 1:Sequencer

Returns the current status of the header.

If started, terminate the connection.

Result format (ResultEntry struct)

u8 packetType // 0xff:Result
u32 length // Total length of the entry
u32 errorNum // Error code (0:OK)
u8[] errorStr

Sequencer entries

Start L2 Block

Entry type = 1

Entry data:

u64 batchNum
u64 blockL2Num
u64 timestamp
u8[32] globalExitRoot
u8[20] coinbase
u16 forkId

L2 TX

Entry type = 2

Entry data:

u8 gasPricePercentage
u8 isValid // Intrinsic
u32 encodedTXLength
u8[] encodedTX

End L2 Block

Entry type = 3

Entry data:

u64 blockL2Num
u256 l2BlockHash
u256 stateRoot

API Interface

Send data

• StartAtomicOp()
• AddStreamBookmark(u8[] bookmark) -> returns u64 entryNumber
• AddStreamEntry(u32 entryType, u8[] data) -> returns u64 entryNumber
• CommitAtomicOp()
• RollbackAtomicOp()

Query data

• GetHeader() -> returns struct HeaderEntry
• GetEntry(u64 entryNumber) -> returns struct FileEntry
• GetBookmark(u8[] bookmark) -> returns u64 entryNumber
• GetFirstEventAfterBookmark(u8[] bookmark) -> returns struct FileEntry

Documentation

Index

• Variables
• func PrintVersion(w io.Writer)

Variables

var (
	Version   = "v0.1.0"
	GitRev    = "undefined"
	GitBranch = "undefined"
	BuildDate = "Fri, 17 Jun 1988 01:58:00 +0200"
)

Populated during build, don't touch!

Functions

func PrintVersion

func PrintVersion(w io.Writer)

PrintVersion prints version info into the provided io.Writer.