Started working on the harness and test-harness crates.

crates/harness/Cargo.lock

@@ -0,0 +1,228 @@
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+# It is not intended for manual editing.
+version = 3
+
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+ "memchr",
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+
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+ "hermit-abi",
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+ "log",
+ "regex",
+ "termcolor",
+]
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+ "serde-block-tree",
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+ "proc-macro2",
+]
+
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+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
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+
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+dependencies = [
+ "serde",
+ "serde-big-array",
+]
+
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+ "quote",
+ "syn",
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+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
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+ "winapi",
+]
+
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crates/harness/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "harness"
+version = "0.0.1"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+serde-block-tree = { path = "../serde-block-tree" }
+serde = { version = "^1.0.136", features = ["derive"] }
+log = "0.4.17"
+
+[dev-dependencies]
+env_logger = "0.9.0"
+ctor = "0.1.22"

crates/harness/src/lib.rs

@@ -0,0 +1,108 @@
+use serde::{Serialize, Deserialize};
+use std::{
+    io::{BufWriter, BufReader, prelude::*},
+    process::{Child, ChildStdin, Command, Stdio},
+    sync::mpsc::{channel, Receiver},
+    time::{Duration},
+};
+use serde_block_tree::{self, write_to, read_from};
+use log::{error};
+
+#[derive(Serialize, Deserialize)]
+pub enum Message {
+    Echo(String),
+}
+
+pub struct Node {
+    child: Child,
+    stdin: BufWriter<ChildStdin>,
+    message_rx: Receiver<Message>,
+}
+
+impl Node {
+    pub fn new() -> Result<Node, std::io::Error> {
+        let mut child = Command::new("blocktree-node")
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::inherit())
+            .spawn()?;
+        let stdin = BufWriter::new(child.stdin.take().unwrap());
+        let mut stdout = BufReader::new(child.stdout.take().unwrap());
+        let (message_tx, message_rx) = channel();
+        std::thread::spawn(move ||  loop {
+            match read_from(&mut stdout) {
+                Ok(msg) => {
+                    match message_tx.send(msg) {
+                        Ok(_) => (),
+                        // Break if the receiver is dead.
+                        Err(_) => break,
+                    }
+                },
+                // Break if the child is dead.
+                Err(serde_block_tree::Error::Eof) => break,
+                Err(serde_block_tree::Error::Io(io_err)) => {
+                    match io_err.kind() {
+                        std::io::ErrorKind::UnexpectedEof => {
+                            error!("The child process closed its stdout stream.");
+                            break;
+                        }
+                        _ => error!("IO error ocurred: {:?}", io_err),
+                    }
+                },
+                Err(err) => error!("Failed to deserialize child message {:?}", err),
+            };
+        });
+        Ok(Node { child, stdin, message_rx })
+    }
+
+    pub fn send(&mut self, msg: &Message) -> serde_block_tree::Result<()> {
+        write_to(&msg, &mut self.stdin)?;
+        self.stdin.flush().map_err(serde_block_tree::Error::Io)?;
+        Ok(())
+    }
+
+    pub fn receive(&mut self, timeout: Duration) -> Option<Message> {
+        match self.message_rx.recv_timeout(timeout) {
+            Ok(msg) => Some(msg),
+            Err(err) => {
+                eprintln!("Failed to receive message from thread. Error: {:?}", err);
+                None
+            }
+        }
+    }
+}
+
+impl Drop for Node {
+    fn drop(&mut self) {
+        let _ = self.child.kill();
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use ctor::ctor;
+    use env_logger;
+
+    #[ctor]
+    fn setup_logging() {
+        env_logger::init();
+    }
+
+    #[test]
+    fn node_new() {
+        Node::new().unwrap();
+    }
+
+    #[test]
+    fn message_echo() {
+        let mut node = Node::new().unwrap();
+        let payload = "Howdy".to_string();
+        node.send(&Message::Echo(payload.clone())).unwrap();
+        let reply = node.receive(Duration::from_millis(100)).unwrap();
+        let reply_payload = match reply {
+            Message::Echo(payload) => Some(payload),
+        };
+        assert_eq!(Some(payload), reply_payload);
+    }
+}

crates/node/Cargo.lock

@@ -2,6 +2,26 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -41,6 +61,19 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "env_logger"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b2cf0344971ee6c64c31be0d530793fba457d322dfec2810c453d0ef228f9c3"
+dependencies = [
+ "atty",
+ "humantime",
+ "log",
+ "regex",
+ "termcolor",
+]
+
 [[package]]
 name = "foreign-types"
 version = "0.3.2"
@@ -56,23 +89,65 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "00b0228411908ca8685dba7fc2cdd70ec9990a6e753e89b6ac91a84c40fbaf4b"
 
+[[package]]
+name = "harness"
+version = "0.0.1"
+dependencies = [
+ "log",
+ "serde",
+ "serde-block-tree",
+]
+
 [[package]]
 name = "heck"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9"
 
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
 [[package]]
 name = "libc"
-version = "0.2.123"
+version = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
+
+[[package]]
+name = "log"
+version = "0.4.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
+name = "memchr"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb691a747a7ab48abc15c5b42066eaafde10dc427e3b6ee2a1cf43db04c763bd"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
 
 [[package]]
 name = "node"
 version = "0.1.0"
 dependencies = [
  "base64-url",
+ "env_logger",
+ "harness",
+ "log",
  "openssl",
  "serde",
  "serde-big-array",
@@ -83,38 +158,50 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.10.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9"
+checksum = "18a6dbe30758c9f83eb00cbea4ac95966305f5a7772f3f42ebfc7fc7eddbd8e1"
 
 [[package]]
 name = "openssl"
-version = "0.10.38"
+version = "0.10.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c7ae222234c30df141154f159066c5093ff73b63204dcda7121eb082fc56a95"
+checksum = "618febf65336490dfcf20b73f885f5651a0c89c64c2d4a8c3662585a70bf5bd0"
 dependencies = [
  "bitflags",
  "cfg-if",
  "foreign-types",
  "libc",
  "once_cell",
+ "openssl-macros",
  "openssl-sys",
 ]
 
+[[package]]
+name = "openssl-macros"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b501e44f11665960c7e7fcf062c7d96a14ade4aa98116c004b2e37b5be7d736c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "openssl-src"
-version = "111.18.0+1.1.1n"
+version = "111.22.0+1.1.1q"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7897a926e1e8d00219127dc020130eca4292e5ca666dd592480d72c3eca2ff6c"
+checksum = "8f31f0d509d1c1ae9cada2f9539ff8f37933831fd5098879e482aa687d659853"
 dependencies = [
  "cc",
 ]
 
 [[package]]
 name = "openssl-sys"
-version = "0.9.72"
+version = "0.9.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e46109c383602735fa0a2e48dd2b7c892b048e1bf69e5c3b1d804b7d9c203cb"
+checksum = "e5f9bd0c2710541a3cda73d6f9ac4f1b240de4ae261065d309dbe73d9dceb42f"
 dependencies = [
  "autocfg",
  "cc",
@@ -132,33 +219,50 @@ checksum = "1df8c4ec4b0627e53bdf214615ad287367e482558cf84b109250b37464dc03ae"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.36"
+version = "1.0.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+checksum = "dd96a1e8ed2596c337f8eae5f24924ec83f5ad5ab21ea8e455d3566c69fbcaf7"
 dependencies = [
- "unicode-xid",
+ "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.15"
+version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "864d3e96a899863136fc6e99f3d7cae289dafe43bf2c5ac19b70df7210c0a145"
+checksum = "3bcdf212e9776fbcb2d23ab029360416bb1706b1aea2d1a5ba002727cbcab804"
 dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c4eb3267174b8c6c2f654116623910a0fef09c4753f8dd83db29c48a0df988b"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244"
+
 [[package]]
 name = "rustversion"
-version = "1.0.6"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2cc38e8fa666e2de3c4aba7edeb5ffc5246c1c2ed0e3d17e560aeeba736b23f"
+checksum = "a0a5f7c728f5d284929a1cccb5bc19884422bfe6ef4d6c409da2c41838983fcf"
 
 [[package]]
 name = "serde"
-version = "1.0.136"
+version = "1.0.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
+checksum = "0171ebb889e45aa68b44aee0859b3eede84c6f5f5c228e6f140c0b2a0a46cad6"
 dependencies = [
  "serde_derive",
 ]
@@ -182,9 +286,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.136"
+version = "1.0.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
+checksum = "dc1d3230c1de7932af58ad8ffbe1d784bd55efd5a9d84ac24f69c72d83543dfb"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -193,18 +297,18 @@ dependencies = [
 
 [[package]]
 name = "strum"
-version = "0.24.0"
+version = "0.24.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e96acfc1b70604b8b2f1ffa4c57e59176c7dbb05d556c71ecd2f5498a1dee7f8"
+checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
 dependencies = [
  "strum_macros",
 ]
 
 [[package]]
 name = "strum_macros"
-version = "0.24.0"
+version = "0.24.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6878079b17446e4d3eba6192bb0a2950d5b14f0ed8424b852310e5a94345d0ef"
+checksum = "4faebde00e8ff94316c01800f9054fd2ba77d30d9e922541913051d1d978918b"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -215,23 +319,63 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.86"
+version = "1.0.98"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
+checksum = "c50aef8a904de4c23c788f104b7dddc7d6f79c647c7c8ce4cc8f73eb0ca773dd"
 dependencies = [
  "proc-macro2",
  "quote",
- "unicode-xid",
+ "unicode-ident",
+]
+
+[[package]]
+name = "termcolor"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bab24d30b911b2376f3a13cc2cd443142f0c81dda04c118693e35b3835757755"
+dependencies = [
+ "winapi-util",
 ]
 
 [[package]]
-name = "unicode-xid"
-version = "0.2.2"
+name = "unicode-ident"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+checksum = "5bd2fe26506023ed7b5e1e315add59d6f584c621d037f9368fea9cfb988f368c"
 
 [[package]]
 name = "vcpkg"
 version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

crates/node/Cargo.toml

@@ -8,9 +8,12 @@ edition = "2021"
 
 [dependencies]
 serde-block-tree = { path = "../serde-block-tree" }
+harness = { path = "../harness" }
 serde = { version = "^1.0.136", features = ["derive"] }
 serde-big-array = { version = "^0.4.1" }
 openssl = { version = "^0.10.38", features = ["vendored"] }
 base64-url = { version = "^1.4.13" }
 strum = { version = "^0.24.0", features = ["derive"] }
 strum_macros = { version = "^0.24.0" }
+env_logger = "0.9.0"
+log = "0.4.17"

crates/node/src/main.rs

@@ -8,10 +8,16 @@ use std::{
     hash::Hash as Hashable,
     fmt::{self, Display, Formatter},
     time::{Duration, SystemTime},
-    ops::{Add, Sub}
+    ops::{Add, Sub},
+    io::{self, BufWriter, Write},
 };
 use serde::{Serialize, Deserialize};
 use serde_big_array::BigArray;
+use log::error;
+use env_logger;
+
+use serde_block_tree::{self, read_from, write_to};
+use harness::Message;
 
 #[cfg(test)]
 mod test_helpers;
@@ -336,8 +342,34 @@ impl Sub<Duration> for Epoch {
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hashable)]
 struct FragmentSerial(u32);
 
+fn send<W: Write>(stdout: &mut BufWriter<W>, msg: &Message) {
+    if let Err(err) = write_to(msg, stdout) {
+        error!("Failed to serialize message {:?}", err);
+        return;
+    }
+    if let Err(err) = stdout.flush() {
+        error!("Failed to flush stdout {:?}", err);
+    }
+}
+
 fn main() {
-    println!("Hello, world!");
+    env_logger::init();
+    let stdin = io::stdin();
+    let mut in_lock = stdin.lock();
+    let stdout = io::stdout();
+    let mut out_lock = BufWriter::new(stdout.lock());
+    loop {
+        let message: Message = match read_from(&mut in_lock) {
+            Err(err) => {
+                error!("Failed to read from stdin {:?}", err);
+                continue;
+            },
+            Ok(message) => message,
+        };
+        match message {
+            Message::Echo(_) => send(&mut out_lock, &message), 
+        }
+    }
 }
 
 #[cfg(test)]

crates/test-harness/Cargo.lock

@@ -0,0 +1,107 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "harness"
+version = "0.0.1"
+dependencies = [
+ "log",
+ "serde",
+ "serde-block-tree",
+]
+
+[[package]]
+name = "log"
+version = "0.4.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd96a1e8ed2596c337f8eae5f24924ec83f5ad5ab21ea8e455d3566c69fbcaf7"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3bcdf212e9776fbcb2d23ab029360416bb1706b1aea2d1a5ba002727cbcab804"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.138"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1578c6245786b9d168c5447eeacfb96856573ca56c9d68fdcf394be134882a47"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde-big-array"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3323f09a748af288c3dc2474ea6803ee81f118321775bffa3ac8f7e65c5e90e7"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "serde-block-tree"
+version = "0.1.0"
+dependencies = [
+ "serde",
+ "serde-big-array",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.138"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "023e9b1467aef8a10fb88f25611870ada9800ef7e22afce356bb0d2387b6f27c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.98"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c50aef8a904de4c23c788f104b7dddc7d6f79c647c7c8ce4cc8f73eb0ca773dd"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "test-harness"
+version = "0.1.0"
+dependencies = [
+ "harness",
+ "serde-block-tree",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5bd2fe26506023ed7b5e1e315add59d6f584c621d037f9368fea9cfb988f368c"

crates/test-harness/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "test-harness"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+serde-block-tree = { path = "../serde-block-tree" }
+harness = { path = "../harness" }

crates/test-harness/src/lib.rs

@@ -0,0 +1,12 @@
+#[cfg(test)]
+use std::{
+    io::{self, Write}
+};
+use harness::Message;
+use serde_block_tree::{write_to, read_from};
+
+#[test]
+fn echo() {
+    unimplemented!();
+}
+

doc/Book/Book.tex

@@ -242,6 +242,23 @@ blocks containing them public (unencrypted), or else provide some mechanism for
 
 \chapter{Data Structures}
 
+\section{Blocks}
+The fundamental cryptographic operations that can be performed on blocks are:
+\begin{itemize}
+\item Encrypt body.
+\item Decrypt body.
+\item Add a writecap.
+\item Sign
+\item Verify
+\end{itemize}
+
+\section{Writecaps}
+The cryptographic operations that can be performed on a writecap are:
+\begin{itemize}
+\item Sign
+\item Verify
+\end{itemize}
+
 \chapter{Nodes}
 
 \chapter{The Network}