From 5c1f3ed5b9a4ed81b669cfeab250116a06abf8fa Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Sat, 20 Jul 2019 17:26:11 -0400
Subject: [PATCH 1/7] hack out the measurements entirely

---
 services/sensor_tracker/Cargo.lock    |  2 +-
 services/sensor_tracker/Cargo.toml    |  2 +-
 services/sensor_tracker/README.md     | 11 +++---
 services/sensor_tracker/src/logic.rs  |  5 ++-
 services/sensor_tracker/src/model.rs  | 41 ++-------------------
 services/sensor_tracker/src/predis.rs | 52 ++++++++-------------------
 6 files changed, 26 insertions(+), 87 deletions(-)

diff --git a/services/sensor_tracker/Cargo.lock b/services/sensor_tracker/Cargo.lock
index 2b6df651..5acc6a59 100644
--- a/services/sensor_tracker/Cargo.lock
+++ b/services/sensor_tracker/Cargo.lock
@@ -514,7 +514,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "sensor_tracker"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "dotenv 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "envy 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/services/sensor_tracker/Cargo.toml b/services/sensor_tracker/Cargo.toml
index 320a2035..74cf0f85 100644
--- a/services/sensor_tracker/Cargo.toml
+++ b/services/sensor_tracker/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sensor_tracker"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Terkwood <metaterkhorn@gmail.com>"]
 edition = "2018"
 
diff --git a/services/sensor_tracker/README.md b/services/sensor_tracker/README.md
index 6930ce25..c22518a5 100644
--- a/services/sensor_tracker/README.md
+++ b/services/sensor_tracker/README.md
@@ -12,25 +12,24 @@ Additionally, it creates an entry in the Redis `<namespace>/sensors/<temp_or_ph>
 
 This is useful for sensors generating temperature and/or pH data.
 
-Such data comes into an MQTT topic looking like this:
+Such data might come into an MQTT topic looking like this:
 
 ```
 { "device_id": <hex>, "temp_f": 81.71, "temp_c": 23.45, "ph": 7.77, "ph_mv": 453.05 }
 ```
 
-If the sensor isn't, it will create the following type of stub record
-for the temp sensor based on a UUID V5 ID conversion:
+If the device hasn't ever been tracked, it will create the following type of stub record with an internal device ID.  The internal device ID is a (namespaced) UUID V5:
 
 ```
-HMSET <namespace>/sensors/<temp_or_ph>/<uuid_v5_id> create_time <epoch>
+HMSET <namespace>/devices/<device_internal_id> create_time <epoch>
 ```
 
 The operator is encouraged to later amend the hash to include
-a helpful reference to the tank which the sensor serves, so
+a helpful reference to the area which the sensing device serves, so
 that the LED status utility can properly format messages.
 
 ```
-HSET <namespace>/sensors/<temp_or_ph>/<device_internal_id> tank 0
+HSET <namespace>/devices/<device_internal_id> area 0
 ```
 
 ### Sample redis records
diff --git a/services/sensor_tracker/src/logic.rs b/services/sensor_tracker/src/logic.rs
index 3dceb591..4ec56bc9 100644
--- a/services/sensor_tracker/src/logic.rs
+++ b/services/sensor_tracker/src/logic.rs
@@ -15,15 +15,14 @@ pub fn receive_updates(
                 if let Some(sensor_message) = prawnqtt::deser_message(paho) {
                     let ext_device_id: &str = &sensor_message.device_id;
 
-                    sensor_message.measurements().iter().for_each(|measure| {
-                        if let Ok(delta_events) = predis::update(redis_ctx, &measure, ext_device_id)
+                        if let Ok(delta_events) = predis::update(redis_ctx, &sensor_message, ext_device_id)
                         {
                             // emit all changed keys & hash field names to redis
                             // on the appropriate redis pub/sub topic.
                             // these will be processed later by the gcloud_push utility
                             predis::publish_updates(redis_ctx, delta_event_topic, delta_events)
                         }
-                    });
+                    ;
                 }
             }
             Err(_) if !mqtt_cli.is_connected() => {
diff --git a/services/sensor_tracker/src/model.rs b/services/sensor_tracker/src/model.rs
index 3628ce5d..1bc50363 100644
--- a/services/sensor_tracker/src/model.rs
+++ b/services/sensor_tracker/src/model.rs
@@ -1,5 +1,8 @@
 /// This message is emitted to an MQTT channel by
 /// some device with access to a temp sensor (DS18B20, etc)
+/// `external_device_id` is usually reported as a
+/// e.g. "28654597090000e4"
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct SensorMessage {
     pub device_id: String,
@@ -13,45 +16,7 @@ pub struct SensorMessage {
     pub heat_index_f: Option<f64>,
 }
 
-/// `external_device_id` is usually reported as a
-/// e.g. "28654597090000e4"
-impl SensorMessage {
-    pub fn measurements(&self) -> Vec<Measurement> {
-        let mut v: Vec<Measurement> = vec![];
-        if let (
-            Some(humidity),
-            Some(status),
-            Some(temp_f),
-            Some(temp_c),
-            Some(heat_index_f),
-            Some(heat_index_c),
-        ) = (
-            self.humidity,
-            &self.status,
-            self.temp_f,
-            self.temp_c,
-            self.heat_index_f,
-            self.heat_index_c,
-        ) {
-            v.push(Measurement::DHT {
-                status: status.to_owned(),
-                humidity,
-                temp_f,
-                temp_c,
-                heat_index_f,
-                heat_index_c,
-            })
-        } else if let (Some(temp_f), Some(temp_c)) = (self.temp_f, self.temp_c) {
-            v.push(Measurement::Temp { temp_f, temp_c })
-        }
 
-        if let (Some(ph), Some(ph_mv)) = (self.ph, self.ph_mv) {
-            v.push(Measurement::PH { ph, ph_mv })
-        }
-
-        v
-    }
-}
 
 #[derive(Debug)]
 pub enum Measurement {
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index 3d60ad78..841b6259 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -13,20 +13,20 @@ use uuid::Uuid;
 /// Will create a new sensor record for this device if one does not already exist.
 pub fn update<'a, 'b>(
     redis_ctx: &RedisContext,
-    measure: &model::Measurement,
+    sensor_message: &model::SensorMessage,
     ext_device_id: &str,
 ) -> Result<Vec<REvent>, redis::RedisError> {
     let mut delta_events: Vec<REvent> = vec![];
 
-    println!("Received redis {} update: {:?}", measure.name(), measure);
+    println!("Received redis update: {:?}", sensor_message);
 
-    let ext_device_namespace = &redis_ctx.get_external_device_namespace(measure.name())?;
+    let ext_device_namespace = &redis_ctx.get_external_device_namespace()?;
     let device_id = internal_device_id(ext_device_id, ext_device_namespace).unwrap();
 
     println!("\tDevice ID (internal): {}", device_id);
     let rn = &redis_ctx.namespace;
 
-    let sensor_set_event = update_sensor_set(redis_ctx, rn, measure, device_id);
+    let sensor_set_event = update_sensor_set(redis_ctx, rn, sensor_message, device_id);
     if let Some(e) = sensor_set_event {
         delta_events.push(e)
     }
@@ -42,12 +42,8 @@ pub fn update<'a, 'b>(
     if let Ok(v) = tank_and_area_and_update_count {
         // Tank associated with this sensor?
         let revent = match (v.get(0).unwrap_or(&None), v.get(1).unwrap_or(&None)) {
-            (Some(tank_num), _) => {
-                update_container_hash(redis_ctx, Container::Tanks, tank_num, &measure)
-            }
-            (_, Some(area_num)) => {
-                update_container_hash(redis_ctx, Container::Areas, area_num, &measure)
-            }
+            (Some(tank_num), _) => update_area_hash(redis_ctx, tank_num, &measure),
+            (_, Some(area_num)) => update_area_hash(redis_ctx, area_num, &measure),
             (None, None) => ensure_sensor_hash_exists(redis_ctx, sensor_hash_key, ext_device_id),
         };
 
@@ -93,39 +89,19 @@ fn update_sensor_set(
     }
 }
 
-enum Container {
-    Tanks,
-    Areas,
-}
-
-impl Container {
-    pub fn to_string(self) -> String {
-        match self {
-            Container::Tanks => "tanks".to_string(),
-            Container::Areas => "areas".to_string(),
-        }
-    }
-}
-
-fn update_container_hash(
+fn update_area_hash(
     redis_ctx: &RedisContext,
-    container: Container,
     container_num: &u64,
     measure: &model::Measurement,
 ) -> Option<REvent> {
     // We found the area associated with this
     // sensor ID, so we should update that area's
     // current reading.
-    let container_key = format!(
-        "{}/{}/{}",
-        redis_ctx.namespace,
-        container.to_string(),
-        container_num
-    );
+    let area_key = format!("{}/areas/{}", redis_ctx.namespace, container_num);
 
-    let container_measure_count: Result<Option<u32>, _> = redis_ctx
+    let area_measure_count: Result<Option<u32>, _> = redis_ctx
         .conn
-        .hget(&container_key, &format!("{}_update_count", measure.name()));
+        .hget(&area_key, &format!("{}_update_count", measure.name()));
 
     let uc_name = format!("{}_update_count", measure.name());
     let ut_name = format!("{}_update_time", measure.name());
@@ -134,7 +110,7 @@ fn update_container_hash(
 
         data.push((
             &uc_name,
-            container_measure_count
+            area_measure_count
                 .unwrap_or(None)
                 .map(|u| u + 1)
                 .unwrap_or(1)
@@ -143,20 +119,20 @@ fn update_container_hash(
 
         data.push((&ut_name, epoch_secs().to_string()));
         (
-            redis_ctx.conn.hset_multiple(&container_key, &data[..]),
+            redis_ctx.conn.hset_multiple(&area_key, &data[..]),
             data.iter().map(|(a, _)| *a).collect(),
         )
     };
 
     match update {
         (Err(e), _) => {
-            println!("update fails for {}: {:?}", container_key, e);
+            println!("update fails for {}: {:?}", area_key, e);
             None
         }
         (Ok(_), fields) if fields.len() > 0 => {
             let fs = fields.iter().map(|s| s.to_string()).collect();
             Some(REvent::HashUpdated {
-                key: container_key.to_string(),
+                key: area_key.to_string(),
                 fields: fs,
             })
         }

From 44cec69876aa19b4b06cfed0cb206e8afde22fee Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Sat, 20 Jul 2019 17:33:08 -0400
Subject: [PATCH 2/7] hack it up

---
 services/redis_context/Cargo.lock     |  4 +++-
 services/redis_context/Cargo.toml     |  4 ++--
 services/redis_context/src/lib.rs     | 13 ++++---------
 services/sensor_tracker/Cargo.lock    |  6 ++----
 services/sensor_tracker/Cargo.toml    |  2 +-
 services/sensor_tracker/src/predis.rs | 28 +++++++++++++--------------
 6 files changed, 26 insertions(+), 31 deletions(-)

diff --git a/services/redis_context/Cargo.lock b/services/redis_context/Cargo.lock
index 5f8415c7..2b8eb013 100644
--- a/services/redis_context/Cargo.lock
+++ b/services/redis_context/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "ascii"
 version = "0.7.1"
@@ -278,7 +280,7 @@ dependencies = [
 
 [[package]]
 name = "redis_context"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/services/redis_context/Cargo.toml b/services/redis_context/Cargo.toml
index 0a8cec4f..44849648 100644
--- a/services/redis_context/Cargo.toml
+++ b/services/redis_context/Cargo.toml
@@ -1,9 +1,9 @@
 [package]
 name = "redis_context"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Terkwood <metaterkhorn@gmail.com>"]
 edition = "2018"
 
 [dependencies]
 redis = "0.9"
-uuid = { version = "0.7", features = ["v4", "v5"] } # v4 is random, v5 is name-based
+uuid = { version = "0.7", features = ["v4", "v5"] }
diff --git a/services/redis_context/src/lib.rs b/services/redis_context/src/lib.rs
index 238a3beb..49fac269 100644
--- a/services/redis_context/src/lib.rs
+++ b/services/redis_context/src/lib.rs
@@ -24,12 +24,9 @@ impl RedisContext {
     }
 
     /// This is the "name" field that will be used to form a V5 UUID
-    pub fn get_external_device_namespace(
-        &self,
-        device_type: String,
-    ) -> Result<Uuid, redis::RedisError> {
+    pub fn get_external_device_namespace(&self) -> Result<Uuid, redis::RedisError> {
         let key = format!("{}/external_device_namespace", self.namespace);
-        let r: Option<String> = self.conn.hget(&key, device_type)?;
+        let r: Option<String> = self.conn.get(&key)?;
 
         match r {
             None => {
@@ -44,20 +41,18 @@ impl RedisContext {
     }
 }
 
-
 pub enum ExternalDevice {
     Temp,
     PH,
-    Unknown
+    Unknown,
 }
 
-
 impl From<String> for ExternalDevice {
     fn from(device_type: String) -> Self {
         match device_type.to_lowercase().trim() {
             "temp" => ExternalDevice::Temp,
             "ph" => ExternalDevice::PH,
-            _ => ExternalDevice::Unknown
+            _ => ExternalDevice::Unknown,
         }
     }
 }
diff --git a/services/sensor_tracker/Cargo.lock b/services/sensor_tracker/Cargo.lock
index 5acc6a59..099b1317 100644
--- a/services/sensor_tracker/Cargo.lock
+++ b/services/sensor_tracker/Cargo.lock
@@ -422,8 +422,7 @@ dependencies = [
 
 [[package]]
 name = "redis_context"
-version = "0.1.0"
-source = "git+https://github.com/Terkwood/prawnalith/?branch=unstable#7087164ca6a90be0389e466a216cdc4cc55ae781"
+version = "0.2.0"
 dependencies = [
  "redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -520,7 +519,7 @@ dependencies = [
  "envy 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "paho-mqtt 0.4.0 (git+https://github.com/Terkwood/paho.mqtt.rust.git?rev=1b72f84)",
  "redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "redis_context 0.1.0 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)",
+ "redis_context 0.2.0",
  "redis_delta 0.1.2",
  "serde 1.0.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.80 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -841,7 +840,6 @@ dependencies = [
 "checksum rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1961a422c4d189dfb50ffa9320bf1f2a9bd54ecb92792fb9477f99a1045f3372"
 "checksum rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0905b6b7079ec73b314d4c748701f6931eb79fd97c668caa3f1899b22b32c6db"
 "checksum redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f0c747d743d48233f9bc3ed3fb00cb84c1d98d8c7f54ed2d4cca9adf461a7ef3"
-"checksum redis_context 0.1.0 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)" = "<none>"
 "checksum regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)" = "4fd4ace6a8cf7860714a2c2280d6c1f7e6a413486c13298bbc86fd3da019402f"
 "checksum regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "2069749032ea3ec200ca51e4a31df41759190a88edca0d2d86ee8bedf7073341"
 "checksum regex-syntax 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f9ec002c35e86791825ed294b50008eea9ddfc8def4420124fbc6b08db834957"
diff --git a/services/sensor_tracker/Cargo.toml b/services/sensor_tracker/Cargo.toml
index 74cf0f85..0438322c 100644
--- a/services/sensor_tracker/Cargo.toml
+++ b/services/sensor_tracker/Cargo.toml
@@ -9,7 +9,7 @@ dotenv = "0.13"
 envy = "0.3"
 paho-mqtt = { git = "https://github.com/Terkwood/paho.mqtt.rust.git", rev = "1b72f84" }
 redis = "0.9"
-redis_context = { git = "https://github.com/Terkwood/prawnalith/", branch = "unstable" }
+redis_context = { path = "../redis_context" }
 redis_delta = { path = "../redis_delta" }
 serde = "1.0"
 serde_derive = "1.0"
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index 841b6259..9fa351a7 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -32,7 +32,7 @@ pub fn update<'a, 'b>(
     }
 
     // lookup associated tank
-    let sensor_hash_key = &format!("{}/sensors/{}/{}", rn, measure.name(), device_id).to_string();
+    let sensor_hash_key = &format!("{}/devices/{}", rn, device_id).to_string();
 
     let tank_and_area_and_update_count: Result<Vec<Option<u64>>, _> = redis_ctx.conn.hget(
         sensor_hash_key,
@@ -54,10 +54,10 @@ pub fn update<'a, 'b>(
         // record a hit on the updates that the sensor has seen
         // and also record the most recent measurement on the record
         // for this individual sensor
-        let sensor_updated = update_sensor_hash(
+        let sensor_updated = update_device_hash(
             redis_ctx,
             sensor_hash_key,
-            measure,
+            sensor_message,
             v.get(2).unwrap_or(&None),
         );
 
@@ -72,18 +72,18 @@ pub fn update<'a, 'b>(
 fn update_sensor_set(
     redis_ctx: &RedisContext,
     rn: &str,
-    measure: &model::Measurement,
+    sensor_message: &model::SensorMessage,
     device_id: Uuid,
 ) -> Option<REvent> {
-    let set_sensor_type_key = format!("{}/sensors/{}", rn, measure.name());
+    let set_device_key = format!("{}/devices", rn);
     // add to the member set if it doesn't already exist
-    let sensors_added: Result<u64, _> = redis_ctx
+    let devices_added: Result<u64, _> = redis_ctx
         .conn
-        .sadd(&set_sensor_type_key, &format!("{}", device_id));
+        .sadd(&set_device_key, &format!("{}", device_id));
 
-    match sensors_added {
+    match devices_added {
         Ok(n) if n > 0 => Some(REvent::SetUpdated {
-            key: set_sensor_type_key,
+            key: set_device_key,
         }),
         _ => None,
     }
@@ -179,10 +179,10 @@ fn ensure_sensor_hash_exists(
     result
 }
 
-fn update_sensor_hash(
+fn update_device_hash(
     redis_ctx: &RedisContext,
-    sensor_hash_key: &str,
-    measure: &model::Measurement,
+    device_hash_key: &str,
+    measure: &model::SensorMessage,
     maybe_sensor_upd_count: &Option<u64>,
 ) -> Option<REvent> {
     let upd_c = &format!("{}_update_count", measure.name());
@@ -197,9 +197,9 @@ fn update_sensor_hash(
     let ut = &format!("{}_update_time", measure.name());
     data.push((ut, epoch_secs().to_string()));
 
-    let redis_result: Result<(), _> = redis_ctx.conn.hset_multiple(sensor_hash_key, &data[..]);
+    let redis_result: Result<(), _> = redis_ctx.conn.hset_multiple(device_hash_key, &data[..]);
     if let Err(e) = redis_result {
-        println!("couldn't update sensor record {}: {:?}", sensor_hash_key, e);
+        println!("couldn't update device record {}: {:?}", device_hash_key, e);
         None
     } else {
         let mut fields: Vec<String> = vec![];

From 0df3c52d72ce7101d18acf7310b97caa711aeb0f Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Sat, 20 Jul 2019 17:37:15 -0400
Subject: [PATCH 3/7] hack it up

---
 services/redis_context/src/lib.rs     | 16 -----------
 services/sensor_tracker/src/predis.rs | 41 +++++++++++++--------------
 2 files changed, 20 insertions(+), 37 deletions(-)

diff --git a/services/redis_context/src/lib.rs b/services/redis_context/src/lib.rs
index 49fac269..17d6fb18 100644
--- a/services/redis_context/src/lib.rs
+++ b/services/redis_context/src/lib.rs
@@ -40,19 +40,3 @@ impl RedisContext {
         }
     }
 }
-
-pub enum ExternalDevice {
-    Temp,
-    PH,
-    Unknown,
-}
-
-impl From<String> for ExternalDevice {
-    fn from(device_type: String) -> Self {
-        match device_type.to_lowercase().trim() {
-            "temp" => ExternalDevice::Temp,
-            "ph" => ExternalDevice::PH,
-            _ => ExternalDevice::Unknown,
-        }
-    }
-}
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index 9fa351a7..94c76dac 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -31,20 +31,19 @@ pub fn update<'a, 'b>(
         delta_events.push(e)
     }
 
-    // lookup associated tank
+    // lookup associated area
     let sensor_hash_key = &format!("{}/devices/{}", rn, device_id).to_string();
 
-    let tank_and_area_and_update_count: Result<Vec<Option<u64>>, _> = redis_ctx.conn.hget(
+    let area_and_sensors_update_count: Result<Vec<Option<u64>>, _> = redis_ctx.conn.hget(
         sensor_hash_key,
-        vec!["tank", "area", &format!("{}_update_count", measure.name())],
+        vec!["area", "sensors_update_count"],
     );
 
-    if let Ok(v) = tank_and_area_and_update_count {
+    if let Ok(v) = area_and_sensors_update_count {
         // Tank associated with this sensor?
-        let revent = match (v.get(0).unwrap_or(&None), v.get(1).unwrap_or(&None)) {
-            (Some(tank_num), _) => update_area_hash(redis_ctx, tank_num, &measure),
-            (_, Some(area_num)) => update_area_hash(redis_ctx, area_num, &measure),
-            (None, None) => ensure_sensor_hash_exists(redis_ctx, sensor_hash_key, ext_device_id),
+        let revent = match v.get(0).unwrap_or(&None) {
+            Some(area_num) => update_area_hash(redis_ctx, area_num, &sensor_message),
+            None  => ensure_device_hash_exists(redis_ctx, sensor_hash_key, ext_device_id),
         };
 
         if let Some(ev) = revent {
@@ -92,7 +91,7 @@ fn update_sensor_set(
 fn update_area_hash(
     redis_ctx: &RedisContext,
     container_num: &u64,
-    measure: &model::Measurement,
+    sensor_message: &model::SensorMessage,
 ) -> Option<REvent> {
     // We found the area associated with this
     // sensor ID, so we should update that area's
@@ -101,12 +100,12 @@ fn update_area_hash(
 
     let area_measure_count: Result<Option<u32>, _> = redis_ctx
         .conn
-        .hget(&area_key, &format!("{}_update_count", measure.name()));
+        .hget(&area_key, &format!("sensors_update_count"));
 
-    let uc_name = format!("{}_update_count", measure.name());
-    let ut_name = format!("{}_update_time", measure.name());
+    let uc_name = format!("sensors_update_count");
+    let ut_name = format!("sensors_update_time");
     let update: (Result<String, _>, Vec<&str>) = {
-        let mut data: Vec<(&str, String)> = measure.to_redis();
+        let mut data: Vec<(&str, String)> = sensor_message.to_redis();
 
         data.push((
             &uc_name,
@@ -140,9 +139,9 @@ fn update_area_hash(
     }
 }
 
-fn ensure_sensor_hash_exists(
+fn ensure_device_hash_exists(
     redis_ctx: &RedisContext,
-    sensor_hash_key: &str,
+    device_hash_key: &str,
     ext_device_id_str: &str,
 ) -> Option<REvent> {
     // We know that there's no associated "tank"
@@ -154,7 +153,7 @@ fn ensure_sensor_hash_exists(
 
     redis_ctx
         .conn
-        .exists(sensor_hash_key)
+        .exists(device_hash_key)
         .iter()
         .for_each(|e: &bool| {
             if !e {
@@ -166,7 +165,7 @@ fn ensure_sensor_hash_exists(
                 ][..];
                 // new sensor, make note of when it is created
                 let _: Result<Vec<bool>, _> =
-                    redis_ctx.conn.hset_multiple(sensor_hash_key, field_vals);
+                    redis_ctx.conn.hset_multiple(device_hash_key, field_vals);
 
                 let fields = vec![cf, ed];
                 result = Some(REvent::HashUpdated {
@@ -182,10 +181,10 @@ fn ensure_sensor_hash_exists(
 fn update_device_hash(
     redis_ctx: &RedisContext,
     device_hash_key: &str,
-    measure: &model::SensorMessage,
+    sensor_message: &model::SensorMessage,
     maybe_sensor_upd_count: &Option<u64>,
 ) -> Option<REvent> {
-    let upd_c = &format!("{}_update_count", measure.name());
+    let upd_c = &format!("sensors_update_count");
     let mut data: Vec<(&str, String)> = vec![(
         upd_c,
         maybe_sensor_upd_count
@@ -193,8 +192,8 @@ fn update_device_hash(
             .unwrap_or(1)
             .to_string(),
     )];
-    data.extend(measure.to_redis());
-    let ut = &format!("{}_update_time", measure.name());
+    data.extend(sensor_message.to_redis());
+    let ut = &format!("sensors_update_time");
     data.push((ut, epoch_secs().to_string()));
 
     let redis_result: Result<(), _> = redis_ctx.conn.hset_multiple(device_hash_key, &data[..]);

From 1e8fa6a97e33ffc71239462fa27eb3c63d395718 Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Sat, 20 Jul 2019 17:44:16 -0400
Subject: [PATCH 4/7] drop the hammer

---
 services/sensor_tracker/src/logic.rs  | 16 +++++++-------
 services/sensor_tracker/src/model.rs  | 31 ++++++++++++++++++++++++++-
 services/sensor_tracker/src/predis.rs | 13 ++++++-----
 3 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/services/sensor_tracker/src/logic.rs b/services/sensor_tracker/src/logic.rs
index 4ec56bc9..09e9f756 100644
--- a/services/sensor_tracker/src/logic.rs
+++ b/services/sensor_tracker/src/logic.rs
@@ -15,14 +15,14 @@ pub fn receive_updates(
                 if let Some(sensor_message) = prawnqtt::deser_message(paho) {
                     let ext_device_id: &str = &sensor_message.device_id;
 
-                        if let Ok(delta_events) = predis::update(redis_ctx, &sensor_message, ext_device_id)
-                        {
-                            // emit all changed keys & hash field names to redis
-                            // on the appropriate redis pub/sub topic.
-                            // these will be processed later by the gcloud_push utility
-                            predis::publish_updates(redis_ctx, delta_event_topic, delta_events)
-                        }
-                    ;
+                    if let Ok(delta_events) =
+                        predis::update(redis_ctx, &sensor_message, ext_device_id)
+                    {
+                        // emit all changed keys & hash field names to redis
+                        // on the appropriate redis pub/sub topic.
+                        // these will be processed later by the gcloud_push utility
+                        predis::publish_updates(redis_ctx, delta_event_topic, delta_events)
+                    };
                 }
             }
             Err(_) if !mqtt_cli.is_connected() => {
diff --git a/services/sensor_tracker/src/model.rs b/services/sensor_tracker/src/model.rs
index 1bc50363..e24cf37c 100644
--- a/services/sensor_tracker/src/model.rs
+++ b/services/sensor_tracker/src/model.rs
@@ -16,7 +16,36 @@ pub struct SensorMessage {
     pub heat_index_f: Option<f64>,
 }
 
-
+impl SensorMessage {
+    pub fn to_redis(&self) -> Vec<(&str, String)> {
+        let mut data = vec![];
+        if let Some(s) = &self.status {
+            data.push(("status", s.to_string()));
+        }
+        if let Some(humidity) = self.humidity {
+            data.push(("humidity", humidity.to_string()));
+        }
+        if let Some(tf) = self.temp_f {
+            data.push(("temp_f", tf.to_string()));
+        }
+        if let Some(tc) = self.temp_c {
+            data.push(("temp_c", tc.to_string()));
+        }
+        if let Some(hf) = self.heat_index_f {
+            data.push(("heat_index_f", hf.to_string()));
+        }
+        if let Some(hc) = self.heat_index_c {
+            data.push(("heat_index_c", hc.to_string()));
+        }
+        if let Some(ph) = self.ph {
+            data.push(("ph", ph.to_string()))
+        }
+        if let Some(ph_mv) = self.ph_mv {
+            data.push(("ph_mv", ph_mv.to_string()))
+        }
+        data
+    }
+}
 
 #[derive(Debug)]
 pub enum Measurement {
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index 94c76dac..ddf65e49 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -34,16 +34,15 @@ pub fn update<'a, 'b>(
     // lookup associated area
     let sensor_hash_key = &format!("{}/devices/{}", rn, device_id).to_string();
 
-    let area_and_sensors_update_count: Result<Vec<Option<u64>>, _> = redis_ctx.conn.hget(
-        sensor_hash_key,
-        vec!["area", "sensors_update_count"],
-    );
+    let area_and_sensors_update_count: Result<Vec<Option<u64>>, _> = redis_ctx
+        .conn
+        .hget(sensor_hash_key, vec!["area", "sensors_update_count"]);
 
     if let Ok(v) = area_and_sensors_update_count {
         // Tank associated with this sensor?
         let revent = match v.get(0).unwrap_or(&None) {
             Some(area_num) => update_area_hash(redis_ctx, area_num, &sensor_message),
-            None  => ensure_device_hash_exists(redis_ctx, sensor_hash_key, ext_device_id),
+            None => ensure_device_hash_exists(redis_ctx, sensor_hash_key, ext_device_id),
         };
 
         if let Some(ev) = revent {
@@ -169,7 +168,7 @@ fn ensure_device_hash_exists(
 
                 let fields = vec![cf, ed];
                 result = Some(REvent::HashUpdated {
-                    key: sensor_hash_key.to_string(),
+                    key: device_hash_key.to_string(),
                     fields,
                 })
             }
@@ -205,7 +204,7 @@ fn update_device_hash(
         data.iter().for_each(|(f, _)| fields.push(f.to_string()));
 
         Some(REvent::HashUpdated {
-            key: sensor_hash_key.to_string(),
+            key: device_hash_key.to_string(),
             fields,
         })
     }

From c8dfee2b2bc4f6c4b1750667308dbe92b0669cce Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Mon, 22 Jul 2019 17:07:50 -0400
Subject: [PATCH 5/7] trim

---
 services/sensor_tracker/src/model.rs  | 68 ---------------------------
 services/sensor_tracker/src/predis.rs |  2 +-
 2 files changed, 1 insertion(+), 69 deletions(-)

diff --git a/services/sensor_tracker/src/model.rs b/services/sensor_tracker/src/model.rs
index e24cf37c..f6bcb128 100644
--- a/services/sensor_tracker/src/model.rs
+++ b/services/sensor_tracker/src/model.rs
@@ -46,71 +46,3 @@ impl SensorMessage {
         data
     }
 }
-
-#[derive(Debug)]
-pub enum Measurement {
-    Temp {
-        temp_f: f64,
-        temp_c: f64,
-    },
-    PH {
-        ph: f64,
-        ph_mv: f64,
-    },
-    /// Digital humidity and temp, e.g. DHT11 sensor
-    DHT {
-        status: String,
-        humidity: f64,
-        temp_f: f64,
-        temp_c: f64,
-        heat_index_f: f64,
-        heat_index_c: f64,
-    },
-}
-
-impl Measurement {
-    pub fn name(&self) -> String {
-        match self {
-            Measurement::Temp {
-                temp_f: _,
-                temp_c: _,
-            } => "temp".to_string(),
-            Measurement::PH { ph: _, ph_mv: _ } => "ph".to_string(),
-            Measurement::DHT {
-                status: _,
-                humidity: _,
-                temp_f: _,
-                temp_c: _,
-                heat_index_f: _,
-                heat_index_c: _,
-            } => "dht".to_string(),
-        }
-    }
-
-    pub fn to_redis(&self) -> Vec<(&str, String)> {
-        match self {
-            Measurement::Temp { temp_f, temp_c } => vec![
-                ("temp_f", temp_f.to_string()),
-                ("temp_c", temp_c.to_string()),
-            ],
-            Measurement::PH { ph, ph_mv } => {
-                vec![("ph", ph.to_string()), ("ph_mv", ph_mv.to_string())]
-            }
-            Measurement::DHT {
-                status,
-                humidity,
-                temp_f,
-                temp_c,
-                heat_index_f,
-                heat_index_c,
-            } => vec![
-                ("status", status.to_string()),
-                ("humidity", humidity.to_string()),
-                ("temp_f", temp_f.to_string()),
-                ("temp_c", temp_c.to_string()),
-                ("heat_index_f", heat_index_f.to_string()),
-                ("heat_index_c", heat_index_c.to_string()),
-            ],
-        }
-    }
-}
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index ddf65e49..55e39c5b 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -70,7 +70,7 @@ pub fn update<'a, 'b>(
 fn update_sensor_set(
     redis_ctx: &RedisContext,
     rn: &str,
-    sensor_message: &model::SensorMessage,
+    sensor_message: &model::SensorMessage, // TODO wat ?
     device_id: Uuid,
 ) -> Option<REvent> {
     let set_device_key = format!("{}/devices", rn);

From 2a3a3788c2d46d00985084cdf65c66c3ce0bf00b Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Thu, 25 Jul 2019 12:44:14 -0400
Subject: [PATCH 6/7] hack version

---
 services/sensor_tracker/Cargo.lock    | 11 ++++++-----
 services/sensor_tracker/Cargo.toml    |  3 ++-
 services/sensor_tracker/src/predis.rs |  4 ++--
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/services/sensor_tracker/Cargo.lock b/services/sensor_tracker/Cargo.lock
index 1442ddb8..1b762e12 100644
--- a/services/sensor_tracker/Cargo.lock
+++ b/services/sensor_tracker/Cargo.lock
@@ -679,8 +679,8 @@ dependencies = [
 
 [[package]]
 name = "redis_context"
-version = "0.1.0"
-source = "git+https://github.com/Terkwood/prawnalith/?branch=unstable#f92a34261f726b904498ff8b34ee5f1a0e810c09"
+version = "0.2.0"
+source = "git+https://github.com/Terkwood/prawnalith/?branch=feature/simplified-sensor-tracker-data#c8dfee2b2bc4f6c4b1750667308dbe92b0669cce"
 dependencies = [
  "redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -689,8 +689,9 @@ dependencies = [
 [[package]]
 name = "redis_delta"
 version = "0.1.2"
-source = "git+https://github.com/Terkwood/prawnalith/?branch=unstable#f92a34261f726b904498ff8b34ee5f1a0e810c09"
+source = "git+https://github.com/Terkwood/prawnalith/?branch=unstable#1a6bf54663c794eb540172b16c2c5a01b674d2a4"
 dependencies = [
+ "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -838,7 +839,7 @@ dependencies = [
  "envy 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "redis_context 0.1.0 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)",
+ "redis_context 0.2.0 (git+https://github.com/Terkwood/prawnalith/?branch=feature/simplified-sensor-tracker-data)",
  "redis_delta 0.1.2 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)",
  "rumqtt 0.30.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1332,7 +1333,7 @@ dependencies = [
 "checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum redis 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f0c747d743d48233f9bc3ed3fb00cb84c1d98d8c7f54ed2d4cca9adf461a7ef3"
-"checksum redis_context 0.1.0 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)" = "<none>"
+"checksum redis_context 0.2.0 (git+https://github.com/Terkwood/prawnalith/?branch=feature/simplified-sensor-tracker-data)" = "<none>"
 "checksum redis_delta 0.1.2 (git+https://github.com/Terkwood/prawnalith/?branch=unstable)" = "<none>"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6b23da8dfd98a84bd7e08700190a5d9f7d2d38abd4369dd1dae651bc40bfd2cc"
diff --git a/services/sensor_tracker/Cargo.toml b/services/sensor_tracker/Cargo.toml
index 20fa1a1a..9fc363c1 100644
--- a/services/sensor_tracker/Cargo.toml
+++ b/services/sensor_tracker/Cargo.toml
@@ -13,7 +13,8 @@ envy = "*"
 rand_core="0.2.2"
 rumqtt = "*"
 redis = "^0.9"
-redis_context = { git = "https://github.com/Terkwood/prawnalith/", branch = "unstable" }
+# TODO restore branch
+redis_context = { git = "https://github.com/Terkwood/prawnalith/", branch = "feature/simplified-sensor-tracker-data" }
 redis_delta = { git = "https://github.com/Terkwood/prawnalith/", branch = "unstable" }
 serde = "*"
 serde_derive = "*"
diff --git a/services/sensor_tracker/src/predis.rs b/services/sensor_tracker/src/predis.rs
index 55e39c5b..0dcf1daf 100644
--- a/services/sensor_tracker/src/predis.rs
+++ b/services/sensor_tracker/src/predis.rs
@@ -26,7 +26,7 @@ pub fn update<'a, 'b>(
     println!("\tDevice ID (internal): {}", device_id);
     let rn = &redis_ctx.namespace;
 
-    let sensor_set_event = update_sensor_set(redis_ctx, rn, sensor_message, device_id);
+    let sensor_set_event = update_devices_set(redis_ctx, rn, sensor_message, device_id);
     if let Some(e) = sensor_set_event {
         delta_events.push(e)
     }
@@ -67,7 +67,7 @@ pub fn update<'a, 'b>(
     Ok(delta_events)
 }
 
-fn update_sensor_set(
+fn update_devices_set(
     redis_ctx: &RedisContext,
     rn: &str,
     sensor_message: &model::SensorMessage, // TODO wat ?

From 7adfe29b0d85f34c0bf3073400aa7bd3d3e4ca02 Mon Sep 17 00:00:00 2001
From: Terkwood <metaterkhorn@gmail.com>
Date: Thu, 25 Jul 2019 12:46:43 -0400
Subject: [PATCH 7/7] =?UTF-8?q?Update=20README.md=20=F0=9F=93=9D?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 services/sensor_tracker/README.md | 32 +++++++++++--------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/services/sensor_tracker/README.md b/services/sensor_tracker/README.md
index 5ae67d93..7a8ffffb 100644
--- a/services/sensor_tracker/README.md
+++ b/services/sensor_tracker/README.md
@@ -20,26 +20,16 @@ Such data might come into an MQTT topic looking like this:
 
 If the device hasn't ever been tracked, it will create the following type of stub record with an internal device ID.  The internal device ID is a (namespaced) UUID V5:
 
-<<<<<<< HEAD
-```
-HMSET <namespace>/devices/<device_internal_id> create_time <epoch>
-=======
 ```text
 HMSET <namespace>/sensors/<temp_or_ph>/<uuid_v5_id> create_time <epoch>
->>>>>>> unstable
 ```
 
 The operator is encouraged to later amend the hash to include
 a helpful reference to the area which the sensing device serves, so
 that the LED status utility can properly format messages.
 
-<<<<<<< HEAD
-```
-HSET <namespace>/devices/<device_internal_id> area 0
-=======
 ```text
 HSET <namespace>/sensors/<temp_or_ph>/<device_internal_id> tank 0
->>>>>>> unstable
 ```
 
 ## Docker builds
@@ -50,9 +40,9 @@ See `build.sh` and `run.sh` for entry points.
 
 #### temp sensor
 
-`> hgetall namespace/sensors/temp/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa`
+`> hgetall namespace/devices/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa`
 
-```
+```text
  1) "create_time"
  2) "1540598539"
  3) "ext_device_id"
@@ -69,11 +59,11 @@ See `build.sh` and `run.sh` for entry points.
 14) "1"
 ```
 
-**pH sensor**
+#### pH sensor
 
-`> hgetall namespace/sensors/ph/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa`
+`> hgetall namespace/devices/aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa`
 
-```
+```text
  1) "low_ph_ref"
  2) "4.00"
  3) "low_mv"
@@ -96,19 +86,19 @@ See `build.sh` and `run.sh` for entry points.
 20) "286cbc98090000bd"
 ```
 
-**tank counter**
+#### area counter
 
-`> get namespace/tanks`
+`> get namespace/areas`
 
-```
+```text
 "1"
 ```
 
-**tank hash**
+#### area hash
 
-`> hgetall namespace/tanks/1`
+`> hgetall namespace/areas/1`
 
-```
+```text
 hgetall namespace/tanks/1
  1) "temp_f"
  2) "81.16"