Read pointer values

Horrible debugging because I didn't correctly consider that reading a
pointer did not advance the reader pointer. I must set it thus back.

1 files changed, 33 insertions, 4 deletions

diff --git a/geoip/ip.lisp b/geoip/ip.lisp
index 63c373f..7098c94 100644
--- a/geoip/ip.lisp
+++ b/geoip/ip.lisp
@@ -59,7 +59,9 @@
   (data-offset -1 :type fixnum))
 
 (defstruct db-reader
-  (db-ptr))
+  (db-ptr)
+  (head-ptr)
+  (data-offset))
 
 (defstruct maxmind-database-metadata
   (node-count 0 :read-only t :type fixnum)
@@ -167,7 +169,10 @@
       (setf type (+ 7 (read-db-char db-ptr))))
     (list type
           (cond
-            ((or (= type 1) (< length 29))
+            ((= type 1)
+             (incf-pointer (db-reader-db-ptr db-ptr) -1)
+             (+ 2 (ash length -3)))
+            ((< length 29)
              length)
             ((= length 29)
              (+ 29 (read-db-char db-ptr)))
@@ -181,16 +186,38 @@
   (loop repeat length
         collect
         (cons
-         (substitute #\- #\_ (mread-data db-ptr))
+         (intern (string-upcase (substitute #\- #\_ (mread-data db-ptr))) :keyword)
          (mread-data db-ptr))))
 
 (defun mread-list (db-ptr length)
   (loop repeat length collect (mread-data db-ptr)))
 
+(defun read-pointer (reader)
+  (let* ((control-byte (read-db-char reader))
+         (size-bits (ldb (byte 2 3) control-byte))
+         (value-bits (ldb (byte 3 0) control-byte)))
+    (ecase size-bits
+      (0 (+ (ash value-bits 8) (read-db-char reader)))
+      (1 (+ (ash value-bits 16) (mread-unsigned reader 2) 2048))
+      (2 (+ (ash value-bits 24) (mread-unsigned reader 3) 526336))
+      (3 (mread-unsigned reader 4)))))
+
+(defun mread-pointer (reader)
+  (with-slots (db-ptr head-ptr data-offset) reader
+    (let* ((target (+ (read-pointer reader) data-offset))
+           (curr-ptr db-ptr)
+           (result))
+      (setf db-ptr (inc-pointer head-ptr target))
+      (setf result (mread-data reader))
+      (setf db-ptr curr-ptr)
+      result)))
+
 (defun mread-data (db-ptr)
   (destructuring-bind (type length) (mread-datafield-metadata db-ptr)
     (ecase type
+      (1 (mread-pointer db-ptr))
       (2 (mread-uft8 db-ptr length))
+      (3 (cons 'double (mread-unsigned db-ptr 8)))
       (4 (bytes-from-foreign db-ptr length))
       ((5 6 9 10) (mread-unsigned db-ptr length))
       (7 (mread-map db-ptr length))
@@ -233,7 +260,9 @@
       (with-slots (node-count) metadata
         (mread-data
          (make-db-reader
-          :db-ptr (inc-pointer ptr (+ data-offset (- record node-count 16)))))))))
+          :db-ptr (inc-pointer ptr (+ data-offset (- record node-count 16)))
+          :head-ptr ptr
+          :data-offset data-offset))))))
 
 (defun integer-to-bits (n bit-count)
   "Convert integer to list of bits (MSB first)"