feat: improve code quality and add concurrency

.gitignore

@@ -1 +1,2 @@
 data
+bin

Makefile

@@ -0,0 +1,5 @@
+build:
+	go build -o ./bin/cosmos-gc ./cmd/cosmos-gc/main.go
+
+install:
+	go install ./cmd/cosmos-gc

README.md

@@ -1,28 +1,41 @@
 # Cosmos Garbage Collector
 
-## Running
+CLI tool to *really* prune a Cosmos SDK full node.
+
+## Assumptions
+
+- Target chain is running Cosmos SDK version v0.46 or v0.47 (does NOT work on v0.45)
+- Full node uses LevelDB (support for other DBs can be added if need be)
+
+## Installing
+
+Using Go:
 
 ```bash
-go run main.go PATH_TO_APP_HOME # eg. ~/.terra
+go install github.com/coinhall/cosmos-gc/cmd/cosmos-gc
 ```
 
-## Notes
+OR, from source:
 
 ```bash
-# Data held in our 10TB archival full node:
-du -sh ./*
-5.6T    ./application.db
-813G    ./blockstore.db
-1022M   ./cs.wal
-104K    ./evidence.db
-4.0K    ./priv_validator_state.json
-3.0G    ./snapshots
-1.5T    ./state.db
-3.3T    ./tx_index.db
-4.0K    ./upgrade-info.json
+git clone https://github.com/coinhall/cosmos-gc
+cd cosmos-gc
+make install
 ```
 
+## Running
+
+Make sure to stop the full node first (if it is running). Then, run the following command:
+
+```bash
+cosmos-gc PATH_TO_APP_HOME # eg. ~/.terra
+```
+
+You may proceed to start the full node after the above command has finished.
+
+## Implementation Notes
+
+- A new db is created to replace the old db as opposed to pruning the old db as deletions are extremely slow
 - Latest block height must be read from each database (ie. cannot read from one db and assume it's the same for all)
 - `state.db` must contain `validatorsKey` for last valset changed height, latest height, latest height + 1, and latest height + 2; else, starting the daemon will result in consensus failure
-- `application.db` holds the AVL tree for Cosmos SDK, iteration itself is already very expensive (worse still for reads and writes)
-- Tested (and working) for chains using Cosmos SDK versions 0.46 and 0.47
+- `application.db` holds the IAVL tree for Cosmos SDK, iteration itself is already very expensive (worse still for reads and writes)

cmd/cosmos-gc/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/coinhall/cosmos-gc/pkg/pruner"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Printf("Usage: cosmos-gc <app_home>\n")
+		os.Exit(1)
+	}
+	appHome := os.Args[1]
+	dataDir := filepath.Join(appHome, "data")
+	fmt.Printf("Using app data dir at [%v]\n", dataDir)
+
+	wg := sync.WaitGroup{}
+	wg.Add(3)
+
+	go func() {
+		defer wg.Done()
+		fmt.Println("[blockstore] starting to prune...")
+		if err := pruner.PruneBlockstoreDB(dataDir); err != nil {
+			fmt.Printf("[blockstore] pruning failed: %v\n", err)
+			return
+		}
+		fmt.Println("[blockstore] pruned successfully!")
+	}()
+
+	go func() {
+		defer wg.Done()
+		fmt.Println("[state] starting to prune...")
+		if err := pruner.PruneStateDB(dataDir); err != nil {
+			fmt.Printf("[state] pruning failed: %v\n", err)
+			return
+		}
+		fmt.Println("[state] pruned successfully!")
+	}()
+
+	go func() {
+		defer wg.Done()
+		fmt.Println("[application] starting to prune...")
+		fmt.Println("[application] WARNING: THIS IS KNOWN TO TAKE A VERY LONG TIME!")
+		if err := pruner.PruneApplicationDB(dataDir); err != nil {
+			fmt.Printf("[application] pruning failed: %v\n", err)
+			return
+		}
+		fmt.Println("[application] pruned successfully!")
+	}()
+
+	wg.Wait()
+}