From ad684286a189372fef4946c4fc2d78c75685bd19 Mon Sep 17 00:00:00 2001
From: Javier Sancho <jsf@jsancho.org>
Date: Fri, 27 Jan 2017 17:08:08 +0100
Subject: [PATCH] Replace VHashes with Hash Tables

---
 src/bongodb.scm  | 69 ++++++++++++++++++------------------------------
 tests/sample.scm | 10 +++----
 2 files changed, 31 insertions(+), 48 deletions(-)

diff --git a/src/bongodb.scm b/src/bongodb.scm
index 3e5dc68..24ced36 100644
--- a/src/bongodb.scm
+++ b/src/bongodb.scm
@@ -16,10 +16,9 @@
 
 
 (define-module (bongodb)
-  #:use-module (ice-9 receive)
-  #:use-module (ice-9 vlist)
   #:use-module (srfi srfi-9)
   #:use-module (srfi srfi-9 gnu)
+  #:use-module (srfi srfi-69)
   #:export (make-collection
 	    collection?
 	    count
@@ -41,10 +40,10 @@
   (table get-table))
 
 (define (make-collection)
-  (make-collection-record vlist-null))
+  (make-collection-record (make-hash-table)))
 
 (define (count col)
-  (vlist-length (get-table col)))
+  (hash-table-size (get-table col)))
 
 (set-record-type-printer! collection
   (lambda (record port)
@@ -56,46 +55,39 @@
 ;;; Working with documents
 
 (define (format-document document)
-  "Return a vhash document ready to store in a collection"
+  "Return an alist document ready to store in a collection"
   (document-with-id
-   (cond ((vhash? document)
-	  document)
+   (cond ((hash-table? document)
+	  (hash-table->alist document))
 	 (else
-	  (alist->vhash document)))))
+	  document))))
 
 (define (document-with-id document)
   "Return always a document with an id"
-  (or (and (vhash-assoc '_id document)
+  (or (and (assoc '_id document)
 	   document)
-      (vhash-cons '_id (gensym) document)))
+      (assoc-set! document '_id (gensym))))
 
 (define (insert col . documents)
-  "Insert documents into the collection and return the new collection"
+  "Insert documents into the collection and return document ids"
   (cond ((null? documents)
-	 (values col '()))
+	 '())
 	(else
 	 (let* ((document (format-document (car documents)))
-		(docid (cdr (vhash-assoc '_id document)))
-		(newcol (make-collection-record (vhash-cons docid document (get-table col)))))
-	   (receive (rescol docids)
-	       (apply insert (cons newcol (cdr documents)))
-	     (values rescol (cons docid docids)))))))
+		(docid (assoc-ref document '_id)))
+	   (hash-table-set! (get-table col) docid document)
+	   (cons docid (apply insert (cons col (cdr documents))))))))
 
 (define (find col filter)
   "Query the collection and return the documents that match with filter"
-  (map vhash->alist (inner-find col filter)))
-
-(define (inner-find col filter)
-  "Query the collection and return the documents that match with filter"
-  (let ((table (get-table col)))
-    (vhash-fold
-     (lambda (key document result)
-       (cond ((match-document? document filter)
-	      (cons document result))
-	     (else
-	      result)))
-     '()
-     table)))
+  (hash-table-fold
+   (get-table col)
+   (lambda (key document result)
+     (cond ((match-document? document filter)
+	    (cons document result))
+	   (else
+	    result)))
+   '()))
 
 (define (match-document? document filter)
   "Try to match the given document with a given filter"
@@ -106,7 +98,7 @@
 
 (define (update col filter . changes)
   "Update selected documents using the given filter"
-  (let ((documents (inner-find col filter)))
+  (let ((documents (find col filter)))
     (apply insert (cons col (map (lambda (doc) (update-document doc changes)) documents)))))
 
 (define (update-document document changes)
@@ -121,13 +113,13 @@
 
 (define ($eq field value)
   (lambda (document)
-    (let ((stored (vhash-assoc field document)))
+    (let ((stored (assoc field document)))
       (and stored
 	   (equal? (cdr stored) value)))))
 
 (define ($exists field)
   (lambda (document)
-    (and (vhash-assoc field document)
+    (and (assoc field document)
 	 #t)))
 
 (define ($not expr)
@@ -146,13 +138,4 @@
 
 (define ($set field value)
   (lambda (document)
-    (vhash-cons field value document)))
-
-	     
-;;; Tools
-
-(define (vhash->alist vhash)
-  (vhash-fold-right
-   (lambda (key value result) (assoc-set! result key value))
-   '()
-   vhash))
+    (assoc-set! document field value)))
diff --git a/tests/sample.scm b/tests/sample.scm
index bd2cc6e..aeccc60 100644
--- a/tests/sample.scm
+++ b/tests/sample.scm
@@ -25,10 +25,10 @@
 (test-assert (collection? col))
 
 ; Insert
-(set! col (insert col
-		  '((a . 1) (b . 2))
-		  '((a . 10) (b . 20))
-		  '((a . 1) (c . "hello world"))))
+(insert col
+	'((a . 1) (b . 2))
+	'((a . 10) (b . 20))
+	'((a . 1) (c . "hello world")))
 (test-eqv 3 (count col))
 
 ; Search
@@ -41,7 +41,7 @@
 (test-eqv 2 (length (find col ($not ($exists 'c)))))
 
 ; Update
-(set! col (update col ($exists 'c) ($set 'c "test")))
+(update col ($exists 'c) ($set 'c "test"))
 (test-eqv 1 (length (find col ($eq 'c "test"))))
 
 (test-end "bongodb")
-- 
2.39.5