public async Task WriteBooksAsync(string filePath, int totalBooksNeeded, bool makeBookTitlesDistinct, CancellationToken cancellationToken)
{
_loadedBookData = JsonConvert.DeserializeObject <List <BookData> >(File.ReadAllText(filePath))
.ToImmutableList();
//Find out how many in db so we can pick up where we left off
int numBooksInDb;
using (var context = new SqlDbContext(_sqlOptions, null))
{
numBooksInDb = await context.Books.IgnoreQueryFilters().CountAsync();
}
var numWritten = 0;
var numToWrite = totalBooksNeeded - numBooksInDb;
while (numWritten < numToWrite)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
//noSql can be null. If so then it doesn't write to CosmosDb
var noSqlBookUpdater = _noSqlOptions != null
? new NoSqlBookUpdater(new NoSqlDbContext(_noSqlOptions))
: null;
using (var sqlDbContext = new SqlDbContext(_sqlOptions, noSqlBookUpdater))
{
var authorsFinder = new AuthorFinder(sqlDbContext);
var batchToAdd = Math.Min(_loadedBookData.Count, numToWrite - numWritten);
var batch = GenerateBooks(batchToAdd, numBooksInDb, makeBookTitlesDistinct, authorsFinder).ToList();
sqlDbContext.AddRange(batch);
await sqlDbContext.SaveChangesAsync();
numWritten += batch.Count;
numBooksInDb += batch.Count;
}
}
}
private IEnumerable <Book> GenerateBooks(int batchToAdd, int numBooksInDb, bool makeBookTitlesDistinct, AuthorFinder authorsFinder)
{
for (int i = numBooksInDb; i < numBooksInDb + batchToAdd; i++)
{
var sectionNum = (int)Math.Truncate(i / (double)NumBooksInSet);
var authors = authorsFinder.GetAuthorsOfThisBook(_loadedBookData[i % _loadedBookData.Count].Authors).ToList();
var title = _loadedBookData[i % _loadedBookData.Count].Title;
if (sectionNum > 0 && makeBookTitlesDistinct)
{
title += $" (copy {sectionNum})";
}
var book = Book.CreateBook(title,
$"Book{i:D4} Description",
_loadedBookData[i % _loadedBookData.Count].PublishDate.AddDays(sectionNum),
"Manning",
(i + 1),
null,
authors).Result;
//setup the author cache value for the SQL Events version
book.AuthorsOrdered = string.Join(", ", authors.Select(x => x.Name));
for (int j = 0; j < i % 12; j++)
{
book.AddReview((Math.Abs(3 - j) % 4) + 2, null, j.ToString());
}
if (i % 7 == 0)
{
book.AddPromotion(book.ActualPrice * 0.5m, "today only - 50% off! ");
}
if (book.Reviews.Any())
{
//setup the reviews cache values for the SQL Events version
book.ReviewsCount = book.Reviews.Count();
book.ReviewsAverageVotes = book.Reviews.Sum(x => x.NumStars) / (double)book.ReviewsCount;
}
yield return(book);
}
}
