ticketvote: Move inventory cache to db.

This commit rewrites the ticketvote inventory cache.

The initial plugin implementations were part of an extremely large
commit that added the tstore backend. The caches were saved to the file
system as a quick and dirty way to get things into production, with the
intention of revisting them at a later date. API was later added that
allowed the plugins to cache data in the tstore database.

The new inventory cache that was added in this commit has an improved
API, better documentation, and was moved off of the file system and
into the tstore database.

politeiad/backendv2/tstorebe/plugins/ticketvote/cmds.go

@@ -9,7 +9,6 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"sort"
 	"strconv"
@@ -23,6 +22,7 @@ import (
 	"github.com/decred/politeia/politeiad/plugins/dcrdata"
 	"github.com/decred/politeia/politeiad/plugins/ticketvote"
 	"github.com/decred/politeia/util"
+	"github.com/pkg/errors"
 )
 
 const (
@@ -153,7 +153,7 @@ func (p *ticketVotePlugin) cmdAuthorize(token []byte, payload string) (string, e
 		return "", err
 	}
 
-	// Update inventory
+	// Update the cached inventory
 	var status ticketvote.VoteStatusT
 	switch a.Action {
 	case ticketvote.AuthActionAuthorize:
@@ -162,9 +162,9 @@ func (p *ticketVotePlugin) cmdAuthorize(token []byte, payload string) (string, e
 		status = ticketvote.VoteStatusUnauthorized
 	default:
 		// Action has already been validated. This should not happen.
-		return "", fmt.Errorf("invalid action %v", a.Action)
+		return "", errors.Errorf("invalid action %v", a.Action)
 	}
-	p.inventoryUpdate(a.Token, status)
+	p.inv.UpdateEntryPreVote(auth.Token, status, auth.Timestamp)
 
 	// Prepare reply
 	ar := ticketvote.AuthorizeReply{
@@ -545,9 +545,9 @@ func (p *ticketVotePlugin) startStandard(token []byte, s ticketvote.Start) (*tic
 		return nil, err
 	}
 
-	// Update inventory
-	p.inventoryUpdateToStarted(vd.Params.Token, ticketvote.VoteStatusStarted,
-		vd.EndBlockHeight)
+	// Update the cached inventory
+	p.inv.UpdateEntryPostVote(vd.Params.Token,
+		ticketvote.VoteStatusStarted, vd.EndBlockHeight)
 
 	// Update active votes cache
 	p.activeVotesAdd(vd)
@@ -689,11 +689,11 @@ func (p *ticketVotePlugin) startRunoffForSub(token []byte, srs startRunoffSubmis
 	// Save vote details
 	err = p.voteDetailsSave(token, vd)
 	if err != nil {
-		return fmt.Errorf("voteDetailsSave %x: %v", token, err)
+		return err
 	}
 
-	// Update inventory
-	p.inventoryUpdateToStarted(vd.Params.Token,
+	// Update the cached inventory
+	p.inv.UpdateEntryPostVote(vd.Params.Token,
 		ticketvote.VoteStatusStarted, vd.EndBlockHeight)
 
 	// Update active votes cache
@@ -1814,28 +1814,43 @@ func (p *ticketVotePlugin) cmdInventory(payload string) (string, error) {
 		return "", err
 	}
 
-	// Get best block. This command does not write any data so we can
-	// use the unsafe best block.
-	bb, err := p.bestBlockUnsafe()
+	// Get the best block. This command does not write
+	// any data so we can use the unsafe best block.
+	bestBlock, err := p.bestBlockUnsafe()
 	if err != nil {
-		return "", fmt.Errorf("bestBlockUnsafe: %v", err)
+		return "", err
 	}
 
 	// Get the inventory
-	ibs, err := p.inventoryByStatus(bb, i.Status, i.Page)
-	if err != nil {
-		return "", fmt.Errorf("invByStatus: %v", err)
-	}
+	tokens := make(map[string][]string, 256)
+	switch i.Status {
+	case ticketvote.VoteStatusInvalid:
+		// No vote status was provided. Return a
+		// page of results for all vote statuses.
+		inv, err := p.inv.GetPage(bestBlock)
+		if err != nil {
+			return "", err
+		}
+		for status, entries := range inv.Entries {
+			statusStr := ticketvote.VoteStatuses[status]
+			tokens[statusStr] = entryTokens(entries)
+		}
 
-	// Prepare reply
-	tokens := make(map[string][]string, len(ibs.Tokens))
-	for k, v := range ibs.Tokens {
-		vs := ticketvote.VoteStatuses[k]
-		tokens[vs] = v
+	default:
+		// A vote status was provided. Return a page of results for the
+		// provided status.
+		entries, err := p.inv.GetPageForStatus(bestBlock, i.Status, i.Page)
+		if err != nil {
+			return "", err
+		}
+		statusStr := ticketvote.VoteStatuses[i.Status]
+		tokens[statusStr] = entryTokens(entries)
 	}
+
+	// Prepare the reply
 	ir := ticketvote.InventoryReply{
 		Tokens:    tokens,
-		BestBlock: ibs.BestBlock,
+		BestBlock: bestBlock,
 	}
 	reply, err := json.Marshal(ir)
 	if err != nil {

politeiad/backendv2/tstorebe/plugins/ticketvote/hooks.go

@@ -64,26 +64,31 @@ func (p *ticketVotePlugin) hookSetRecordStatusPost(payload string) error {
 		return err
 	}
 
-	// Ticketvote caches only need to be updated for vetted records
-	if srs.RecordMetadata.State == backend.StateUnvetted {
+	// ticketvote plugin commands can only be run on
+	// vetted records. We can skip all hooks when the
+	// record is not vetted.
+	recordMD := srs.RecordMetadata
+	if recordMD.State == backend.StateUnvetted {
 		return nil
 	}
 
-	// Update the inventory cache
-	switch srs.RecordMetadata.Status {
+	// Update the cached inventory
+	switch recordMD.Status {
 	case backend.StatusPublic:
-		// Add to inventory
-		p.inventoryAdd(srs.RecordMetadata.Token,
-			ticketvote.VoteStatusUnauthorized)
+		// Add a new entry to the inventory for this record
+		p.inv.AddEntry(recordMD.Token, ticketvote.VoteStatusUnauthorized,
+			recordMD.Timestamp)
+
 	case backend.StatusCensored, backend.StatusArchived:
-		// These statuses do not allow for a vote. Mark as ineligible.
-		p.inventoryUpdate(srs.RecordMetadata.Token,
-			ticketvote.VoteStatusIneligible)
+		// These statuses are not allowed to be voted on. Update the inventory
+		// to reflect that this record is ineligible for a vote.
+		p.inv.UpdateEntryPreVote(recordMD.Token, ticketvote.VoteStatusIneligible,
+			recordMD.Timestamp)
 	}
 
-	// Update cached vote metadata
-	return p.voteMetadataCacheOnStatusChange(srs.RecordMetadata.Token,
-		srs.RecordMetadata.State, srs.RecordMetadata.Status, srs.Record.Files)
+	// Update the cached vote metadata
+	return p.voteMetadataCacheOnStatusChange(recordMD.Token,
+		recordMD.State, recordMD.Status, srs.Record.Files)
 }
 
 // linkByVerify verifies that the provided link by timestamp meets all