X-Git-Url: http://dolda2000.com/gitweb/?p=didex.git;a=blobdiff_plain;f=didex%2Findex.py;h=cdd40695600e4bd70b9ae5c2c3d05df6fb237ae0;hp=a1ca06182a5c43ca322cc78d7350486cc66082db;hb=bd14729f305c077e65963fba4aeaab3baf8ee653;hpb=eb2746916b1d19ab025714925d8d254716c498e3

diff --git a/didex/index.py b/didex/index.py
index a1ca061..cdd4069 100644
--- a/didex/index.py
+++ b/didex/index.py
@@ -1,7 +1,9 @@
-import struct, contextlib
+import struct, contextlib, math
 from . import db, lib
 from .db import bd, txnfun
 
+__all__ = ["maybe", "t_int", "t_uint", "t_float", "t_str", "ordered"]
+
 deadlock = bd.DBLockDeadlockError
 notfound = bd.DBNotFoundError
 
@@ -47,7 +49,64 @@ class maybe(object):
         else:
             return self.bk.compare(a[1:], b[1:])
 
-t_int = simpletype.struct(">Q")
+class compound(object):
+    def __init__(self, *parts):
+        self.parts = parts
+
+    def encode(self, obs):
+        if len(obs) != len(self.parts):
+            raise ValueError("invalid length of compound data: " + str(len(obs)) + ", rather than " + len(self.parts))
+        buf = bytearray()
+        for ob, part in zip(obs, self.parts):
+            dat = part.encode(ob)
+            if len(dat) < 128:
+                buf.append(0x80 | len(dat))
+                buf.extend(dat)
+            else:
+                buf.extend(struct.pack(">i", len(dat)))
+                buf.extend(dat)
+        return bytes(buf)
+    def decode(self, dat):
+        ret = []
+        off = 0
+        for part in self.parts:
+            if dat[off] & 0x80:
+                ln = dat[off] & 0x7f
+                off += 1
+            else:
+                ln = struct.unpack(">i", dat[off:off + 4])[0]
+                off += 4
+            ret.append(part.decode(dat[off:off + len]))
+            off += len
+        return tuple(ret)
+    def compare(self, al, bl):
+        if (len(al) != len(self.parts)) or (len(bl) != len(self.parts)):
+            raise ValueError("invalid length of compound data: " + str(len(al)) + ", " + str(len(bl)) + ", rather than " + len(self.parts))
+        for a, b, part in zip(al, bl, self.parts):
+            c = part.compare(a, b)
+            if c != 0:
+                return c
+        return 0
+
+def floatcmp(a, b):
+    if math.isnan(a) and math.isnan(b):
+        return 0
+    elif math.isnan(a):
+        return -1
+    elif math.isnan(b):
+        return 1
+    elif a < b:
+        return -1
+    elif a > b:
+        return 1
+    else:
+        return 0
+
+t_int = simpletype.struct(">q")
+t_uint = simpletype.struct(">Q")
+t_float = simpletype.struct(">d")
+t_float.compare = floatcmp
+t_str = simpletype((lambda ob: ob.encode("utf-8")), (lambda dat: dat.decode("utf-8")))
 
 class index(object):
     def __init__(self, db, name, datatype):