use log and env_logger, and add some logging around sync

taskchampion/Cargo.toml

@@ -13,6 +13,7 @@ failure = {version = "^0.1.5", features = ["derive"] }
 kv = {version = "^0.10.0", features = ["msgpack-value"]}
 lmdb-rkv = {version = "^0.12.3"}
 ureq = "^1.5.2"
+log = "^0.4.11"
 
 [dev-dependencies]
 proptest = "^0.9.4"

taskchampion/src/replica.rs

@@ -6,6 +6,7 @@ use crate::taskdb::TaskDB;
 use crate::taskstorage::{KVStorage, Operation, TaskMap, TaskStorage};
 use chrono::Utc;
 use failure::Fallible;
+use log::trace;
 use std::collections::HashMap;
 use uuid::Uuid;
 
@@ -128,6 +129,7 @@ impl Replica {
     pub fn new_task(&mut self, status: Status, description: String) -> Fallible<Task> {
         let uuid = Uuid::new_v4();
         self.taskdb.apply(Operation::Create { uuid })?;
+        trace!("task {} created", uuid);
         let mut task = Task::new(uuid, TaskMap::new()).into_mut(self);
         task.set_description(description)?;
         task.set_status(status)?;
@@ -144,7 +146,9 @@ impl Replica {
         if self.taskdb.get_task(&uuid)?.is_none() {
             return Err(Error::DBError(format!("Task {} does not exist", uuid)).into());
         }
-        self.taskdb.apply(Operation::Delete { uuid: *uuid })
+        self.taskdb.apply(Operation::Delete { uuid: *uuid })?;
+        trace!("task {} deleted", uuid);
+        Ok(())
     }
 
     /// Synchronize this replica against the given server.

taskchampion/src/task.rs

@@ -2,6 +2,7 @@ use crate::replica::Replica;
 use crate::taskstorage::TaskMap;
 use chrono::prelude::*;
 use failure::Fallible;
+use log::trace;
 use uuid::Uuid;
 
 pub type Timestamp = DateTime<Utc>;
@@ -230,6 +231,7 @@ impl<'r> TaskMut<'r> {
             let now = format!("{}", Utc::now().timestamp());
             self.replica
                 .update_task(self.task.uuid, "modified", Some(now.clone()))?;
+            trace!("task {}: set property modified={:?}", self.task.uuid, now);
             self.task.taskmap.insert(String::from("modified"), now);
             self.updated_modified = true;
         }
@@ -242,8 +244,10 @@ impl<'r> TaskMut<'r> {
             .update_task(self.task.uuid, property, value.as_ref())?;
 
         if let Some(v) = value {
+            trace!("task {}: set property {}={:?}", self.task.uuid, property, v);
             self.task.taskmap.insert(property.to_string(), v);
         } else {
+            trace!("task {}: remove property {}", self.task.uuid, property);
             self.task.taskmap.remove(property);
         }
         Ok(())

taskchampion/src/taskdb.rs

@@ -2,6 +2,7 @@ use crate::errors::Error;
 use crate::server::{AddVersionResult, GetVersionResult, Server};
 use crate::taskstorage::{Operation, TaskMap, TaskStorage, TaskStorageTxn};
 use failure::{format_err, Fallible};
+use log::{info, trace, warn};
 use serde::{Deserialize, Serialize};
 use std::collections::HashSet;
 use std::str;
@@ -172,10 +173,12 @@ impl TaskDB {
         // version twice, then we have diverged.
         let mut requested_parent_version_id = None;
         loop {
+            trace!("beginning sync outer loop");
             let mut base_version_id = txn.base_version()?;
 
             // first pull changes and "rebase" on top of them
             loop {
+                trace!("beginning sync inner loop");
                 if let GetVersionResult::Version {
                     version_id,
                     history_segment,
@@ -184,14 +187,14 @@ impl TaskDB {
                 {
                     let version_str = str::from_utf8(&history_segment).unwrap();
                     let version: Version = serde_json::from_str(version_str).unwrap();
-                    println!("applying version {:?} from server", version_id);
 
                     // apply this verison and update base_version in storage
+                    info!("applying version {:?} from server", version_id);
                     TaskDB::apply_version(txn.as_mut(), version)?;
                     txn.set_base_version(version_id)?;
                     base_version_id = version_id;
                 } else {
-                    println!("no child versions of {:?}", base_version_id);
+                    info!("no child versions of {:?}", base_version_id);
                     // at the moment, no more child versions, so we can try adding our own
                     break;
                 }
@@ -199,24 +202,26 @@ impl TaskDB {
 
             let operations: Vec<Operation> = txn.operations()?.to_vec();
             if operations.is_empty() {
-                println!("no changes to push to server");
+                info!("no changes to push to server");
                 // nothing to sync back to the server..
                 break;
             }
 
+            trace!("sending {} operations to the server", operations.len());
+
             // now make a version of our local changes and push those
             let new_version = Version { operations };
             let history_segment = serde_json::to_string(&new_version).unwrap().into();
-            println!("sending new version to server");
+            info!("sending new version to server");
             match server.add_version(base_version_id, history_segment)? {
                 AddVersionResult::Ok(new_version_id) => {
-                    println!("version {:?} received by server", new_version_id);
+                    info!("version {:?} received by server", new_version_id);
                     txn.set_base_version(new_version_id)?;
                     txn.set_operations(vec![])?;
                     break;
                 }
                 AddVersionResult::ExpectedParentVersion(parent_version_id) => {
-                    println!(
+                    info!(
                         "new version rejected; must be based on {:?}",
                         parent_version_id
                     );
@@ -264,22 +269,31 @@ impl TaskDB {
         // it.  If it happens for server op, then we must copy the remaining local ops.
         let mut local_operations: Vec<Operation> = txn.operations()?;
         for server_op in version.operations.drain(..) {
+            trace!(
+                "rebasing local operations onto server operation {:?}",
+                server_op
+            );
             let mut new_local_ops = Vec::with_capacity(local_operations.len());
             let mut svr_op = Some(server_op);
             for local_op in local_operations.drain(..) {
                 if let Some(o) = svr_op {
-                    let (new_server_op, new_local_op) = Operation::transform(o, local_op);
+                    let (new_server_op, new_local_op) = Operation::transform(o, local_op.clone());
+                    trace!("local operation {:?} -> {:?}", local_op, new_local_op);
                     svr_op = new_server_op;
                     if let Some(o) = new_local_op {
                         new_local_ops.push(o);
                     }
                 } else {
+                    trace!(
+                        "local operation {:?} unchanged (server operation consumed)",
+                        local_op
+                    );
                     new_local_ops.push(local_op);
                 }
             }
             if let Some(o) = svr_op {
                 if let Err(e) = TaskDB::apply_op(txn, &o) {
-                    println!("Invalid operation when syncing: {} (ignored)", e);
+                    warn!("Invalid operation when syncing: {} (ignored)", e);
                 }
             }
             local_operations = new_local_ops;