func WriteRow(ctx context.Context, table *bigtable.Table, columnFamilySep string, rowKey string, columns []string, rowCells []string, startCellIndex int) {
mut := bigtable.NewMutation()
for i := startCellIndex; i < len(rowCells); i++ {
var colSet = strings.Split(columns[i], columnFamilySep)
fam := colSet[0]
col := colSet[1]
mut.Set(fam, col, 0, []byte(rowCells[i]))
}
fmt.Println("Applying row: ", rowKey)
if err := table.Apply(ctx, rowKey, mut); err != nil {
fmt.Println("Error on Mutating row %v: %v", rowKey, err)
}
}
// handleAddDoc adds a document to the index.
func handleAddDoc(w http.ResponseWriter, r *http.Request, table *bigtable.Table) {
if r.Method != "POST" {
http.Error(w, "POST requests only", http.StatusMethodNotAllowed)
return
}
ctx, _ := context.WithTimeout(context.Background(), time.Minute)
name := r.FormValue("name")
if len(name) == 0 {
http.Error(w, "Empty document name!", http.StatusBadRequest)
return
}
content := r.FormValue("content")
if len(content) == 0 {
http.Error(w, "Empty document content!", http.StatusBadRequest)
return
}
var (
writeErr error // Set if any write fails.
mu sync.Mutex // Protects writeErr
wg sync.WaitGroup // Used to wait for all writes to finish.
)
// writeOneColumn writes one column in one row, updates err if there is an error,
// and signals wg that one operation has finished.
writeOneColumn := func(row, family, column, value string, ts bigtable.Timestamp) {
mut := bigtable.NewMutation()
mut.Set(family, column, ts, []byte(value))
err := table.Apply(ctx, row, mut)
if err != nil {
mu.Lock()
writeErr = err
mu.Unlock()
}
}
// Start a write to store the document content.
wg.Add(1)
go func() {
writeOneColumn(name, contentColumnFamily, "", content, bigtable.Now())
wg.Done()
}()
// Start writes to store the document name in the index for each word in the document.
words := tokenize(content)
for _, word := range words {
var (
row = word
family = indexColumnFamily
column = name
value = ""
ts = bigtable.Now()
)
wg.Add(1)
go func() {
// TODO: should use a semaphore to limit the number of concurrent writes.
writeOneColumn(row, family, column, value, ts)
wg.Done()
}()
}
wg.Wait()
if writeErr != nil {
http.Error(w, "Error writing to Bigtable: "+writeErr.Error(), http.StatusInternalServerError)
return
}
var buf bytes.Buffer
if err := addTemplate.ExecuteTemplate(&buf, "", struct{ Title string }{name}); err != nil {
http.Error(w, "Error executing HTML template: "+err.Error(), http.StatusInternalServerError)
return
}
io.Copy(w, &buf)
}