Configurable history size in master (#2606)

* split journaldb commit into two functions: journal_under and mark_canonical

* use new commit mechanism in client

* Configurable history size in master

* Reduce DB history

* Configurable history size

* Set min history size

* Test

* Fixed a test and reduced the limit

parity/cli/config.full.toml

@@ -77,6 +77,7 @@ notify_work = ["http://localhost:3001"]
 [footprint]
 tracing = "auto"
 pruning = "auto"
+pruning_history = 64
 cache_size_db = 64
 cache_size_blocks = 8
 cache_size_queue = 50

parity/cli/config.toml

@@ -46,6 +46,7 @@ tx_queue_gas = "auto"
 [footprint]
 tracing = "on"
 pruning = "fast"
+pruning_history = 64
 cache_size_db = 128
 cache_size_blocks = 16
 cache_size_queue = 100

parity/cli/mod.rs

@@ -207,6 +207,8 @@ usage! {
 			or |c: &Config| otry!(c.footprint).tracing.clone(),
 		flag_pruning: String = "auto",
 			or |c: &Config| otry!(c.footprint).pruning.clone(),
+		flag_pruning_history: u64 = 64u64,
+			or |c: &Config| otry!(c.footprint).pruning_history.clone(),
 		flag_cache_size_db: u32 = 64u32,
 			or |c: &Config| otry!(c.footprint).cache_size_db.clone(),
 		flag_cache_size_blocks: u32 = 8u32,
@@ -361,6 +363,7 @@ struct Mining {
 struct Footprint {
 	tracing: Option<String>,
 	pruning: Option<String>,
+	pruning_history: Option<u64>,
 	fast_and_loose: Option<bool>,
 	cache_size: Option<u32>,
 	cache_size_db: Option<u32>,
@@ -536,6 +539,7 @@ mod tests {
 			// -- Footprint Options
 			flag_tracing: "auto".into(),
 			flag_pruning: "auto".into(),
+			flag_pruning_history: 64u64,
 			flag_cache_size_db: 64u32,
 			flag_cache_size_blocks: 8u32,
 			flag_cache_size_queue: 50u32,
@@ -690,6 +694,7 @@ mod tests {
 			footprint: Some(Footprint {
 				tracing: Some("on".into()),
 				pruning: Some("fast".into()),
+				pruning_history: Some(64),
 				fast_and_loose: None,
 				cache_size: None,
 				cache_size_db: Some(128),

parity/cli/usage.txt

@@ -209,6 +209,8 @@ Footprint Options:
                            fast - maintain journal overlay. Fast but 50MB used.
                            auto - use the method most recently synced or
                            default to fast if none synced (default: {flag_pruning}).
+  --pruning-history NUM    Set a number of recent states to keep when pruning
+                           is active. [default: {flag_pruning_history}].
   --cache-size-db MB       Override database cache size (default: {flag_cache_size_db}).
   --cache-size-blocks MB   Specify the prefered size of the blockchain cache in
                            megabytes (default: {flag_cache_size_blocks}).