Enhance manifest_dump to print each individual edit.

Summary:
The manifest file contains a series of edits. If the verbose
option is switched on, then print each individual edit in the
manifest file. This helps in debugging.

Test Plan: make clean manifest_dump

Reviewers: emayanke, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6807

db/version_set.cc

@@ -1099,7 +1099,8 @@ Status VersionSet::Recover() {
   return s;
 }
 
-Status VersionSet::DumpManifest(Options& options, std::string& dscname) {
+Status VersionSet::DumpManifest(Options& options, std::string& dscname,
+  bool verbose) {
   struct LogReporter : public log::Reader::Reporter {
     Status* status;
     virtual void Corruption(size_t bytes, const Status& s) {
@@ -1122,6 +1123,7 @@ Status VersionSet::DumpManifest(Options& options, std::string& dscname) {
   uint64_t last_sequence = 0;
   uint64_t log_number = 0;
   uint64_t prev_log_number = 0;
+  int count = 0;
   VersionSet::Builder builder(this, current_);
 
   {
@@ -1142,6 +1144,13 @@ Status VersionSet::DumpManifest(Options& options, std::string& dscname) {
         }
       }
 
+      // Write out each individual edit
+      if (verbose) {
+        printf("*************************Edit[%d] = %s\n", 
+                count, edit.DebugString().c_str());
+      }
+      count++;
+
       if (s.ok()) {
         builder.Apply(&edit);
       }

db/version_set.h

@@ -286,7 +286,8 @@ class VersionSet {
   const char* LevelSummary(LevelSummaryStorage* scratch) const;
 
   // printf contents (for debugging)
-  Status DumpManifest(Options& options, std::string& manifestFileName);
+  Status DumpManifest(Options& options, std::string& manifestFileName,
+                      bool verbose);
 
   // Return a human-readable short (single-line) summary of the data size
   // of files per level.  Uses *scratch as backing store.

tools/manifest_dump.cc

@@ -60,7 +60,7 @@ int main(int argc, char** argv) {
 
   VersionSet* versions = new VersionSet(dbname, &options,
                                    tc, cmp);
-  Status s = versions->DumpManifest(options, file);
+  Status s = versions->DumpManifest(options, file, verbose);
   if (!s.ok()) {
     printf("Error in processing file %s %s\n", manifestfile.c_str(),
            s.ToString().c_str());