4 files changed, 104 insertions, 2 deletions

diff --git a/sca-cpp/trunk/components/constdb/client-test.cpp b/sca-cpp/trunk/components/constdb/client-test.cpp
index b796ef01dd..165e3d8836 100644
--- a/sca-cpp/trunk/components/constdb/client-test.cpp
+++ b/sca-cpp/trunk/components/constdb/client-test.cpp
@@ -77,6 +77,32 @@ const bool testConstDb() {
         assert(hasContent(val));
         assert(content(val) == b);
     }
+
+    const list<value> k = nilListValue + "content" + (nilListValue + "item" 
+            + (nilListValue + "name" + string("Apple"))
+            + (nilListValue + "price" + string("$3.99")));
+    const list<value> c = nilListValue + (nilListValue + "entry" 
+            + (nilListValue + "title" + string("item"))
+            + (nilListValue + "id" + string("cart-53d67a61-aa5e-4e5e-8401-39edeba8b83b"))
+            + k);
+
+    {
+        const list<value> s = nilListValue + "content" +
+            (nilListValue + "patch" + string("(define (patch id e) (tree-subst-assoc '(price) '(price \"$3.99\") e))"));
+        const list<value> ps = nilListValue + (nilListValue + "entry" 
+                + (nilListValue + "title" + string("item"))
+                + (nilListValue + "id" + string("cart-53d67a61-aa5e-4e5e-8401-39edeba8b83b"))
+                + s);
+
+        const failable<value> r = http::patch(ps, uri + p, cs);
+        assert(hasContent(r));
+        assert(content(r) == trueValue);
+    }
+    {
+        const failable<value> val = http::get(uri + p, cs);
+        assert(hasContent(val));
+        assert(content(val) == c);
+    }
     {
         const failable<value> r = http::del(uri + p, cs);
         assert(hasContent(r));
diff --git a/sca-cpp/trunk/components/constdb/constdb.cpp b/sca-cpp/trunk/components/constdb/constdb.cpp
index a9a5bc5817..2d34ed2b73 100644
--- a/sca-cpp/trunk/components/constdb/constdb.cpp
+++ b/sca-cpp/trunk/components/constdb/constdb.cpp
@@ -63,6 +63,39 @@ const failable<value> put(const list<value>& params, const tinycdb::TinyCDB& cdb
 }
 
 /**
+ * Patch an item in the database.
+ */
+const failable<value> patch(const list<value>& params, const tinycdb::TinyCDB& cdb) {
+    // Read patch
+    value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
+    if (isNil(p))
+        return mkfailure<value>("Couldn't read patch script");
+    const string script = cadr<value>(p);
+    debug(script, "tinycdb::patch::script");
+    istringstream is(script);
+
+    // Get existing value from database
+    const failable<value> ival = tinycdb::get(car(params), cdb);
+    if (!hasContent(ival) && rcode(ival) != 404)
+        return mkfailure<value>(ival);
+
+    // Apply patch
+    scheme::Env env = scheme::setupEnvironment();
+    const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(car(params), hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
+    if (isNil(pval)) {
+        ostringstream os;
+        os << "Couldn't patch tinycdb entry: " << car(params);
+        return mkfailure<value>(str(os), 404, false);
+    }
+
+    // Push patched value to database
+    const failable<bool> val = tinycdb::patch(car(params), pval, cdb);
+    if (!hasContent(val))
+        return mkfailure<value>(val);
+    return value(content(val));
+}
+
+/**
  * Delete an item from the database.
  */
 const failable<value> del(const list<value>& params, const tinycdb::TinyCDB& cdb) {
@@ -89,6 +122,8 @@ const failable<value> start(unused const list<value>& params) {
             return post(cdr(params), cdb);
         if (func == "put")
             return put(cdr(params), cdb);
+        if (func == "patch")
+            return patch(cdr(params), cdb);
         if (func == "delete")
             return del(cdr(params), cdb);
         return mkfailure<value>();
diff --git a/sca-cpp/trunk/components/constdb/tinycdb-test.cpp b/sca-cpp/trunk/components/constdb/tinycdb-test.cpp
index 6cc9e9eabb..41bfe12772 100644
--- a/sca-cpp/trunk/components/constdb/tinycdb-test.cpp
+++ b/sca-cpp/trunk/components/constdb/tinycdb-test.cpp
@@ -40,6 +40,8 @@ const bool testTinyCDB() {
     assert((get(k, cdb)) == value(string("AAA")));
     assert(hasContent(put(k, string("aaa"), cdb)));
     assert((get(k, cdb)) == value(string("aaa")));
+    assert(hasContent(patch(k, string("bbb"), cdb)));
+    assert((get(k, cdb)) == value(string("bbb")));
     assert(hasContent(del(k, cdb)));
     assert(!hasContent(get(k, cdb)));
 
diff --git a/sca-cpp/trunk/components/constdb/tinycdb.hpp b/sca-cpp/trunk/components/constdb/tinycdb.hpp
index ce1dcbb011..3da5f3c216 100644
--- a/sca-cpp/trunk/components/constdb/tinycdb.hpp
+++ b/sca-cpp/trunk/components/constdb/tinycdb.hpp
@@ -389,6 +389,37 @@ const failable<bool> put(const value& key, const value& val, const TinyCDB& cdb)
 }
 
 /**
+ * Patch an item in the database. If the item doesn't exist it is added.
+ */
+const failable<bool> patch(const value& key, const value& val, const TinyCDB& cdb) {
+    debug(key, "tinycdb::patch::key");
+    debug(val, "tinycdb::patch::value");
+    debug(dbname(cdb), "tinycdb::patch::dbname");
+
+    const string ks(write(content(scheme::writeValue(key))));
+    const string vs(write(content(scheme::writeValue(val))));
+
+    // Process each entry and skip existing key
+    const lambda<const failable<bool>(buffer&, const unsigned int, const unsigned int)> update = [ks](buffer& buf, const unsigned int klen, unused const unsigned int vlen) -> const failable<bool> {
+        if (ks == string((char*)buf, klen))
+            return false;
+        return true;
+    };
+
+    // Add the new entry to the db
+    const lambda<const failable<bool>(struct cdb_make&)> finish = [ks, vs](struct cdb_make& cdbm) -> const failable<bool> {
+        if (cdb_make_add(&cdbm, c_str(ks), (unsigned int)length(ks), c_str(vs), (unsigned int)length(vs)) == -1)
+            return mkfailure<bool>(string("Couldn't add tinycdb entry: ") + ks);
+        return true;
+    };
+
+    // Rewrite the db
+    const failable<bool> r = rewrite(update, finish, cdb);
+    debug(r, "tinycdb::patch::result");
+    return r;
+}
+
+/**
  * Get an item from the database.
  */
 const failable<value> get(const value& key, const TinyCDB& cdb) {
@@ -425,11 +456,14 @@ const failable<bool> del(const value& key, const TinyCDB& cdb) {
     debug(dbname(cdb), "tinycdb::delete::dbname");
 
     const string ks(write(content(scheme::writeValue(key))));
+    bool found = false;
 
     // Process each entry and skip existing key
-    const lambda<const failable<bool>(buffer&, const unsigned int, const unsigned int)> update = [ks](buffer& buf, const unsigned int klen, unused const unsigned int vlen) -> const failable<bool> {
-        if (ks == string((char*)buf, klen))
+    const lambda<const failable<bool>(buffer&, const unsigned int, const unsigned int)> update = [ks, &found](buffer& buf, const unsigned int klen, unused const unsigned int vlen) -> const failable<bool> {
+        if (ks == string((char*)buf, klen)) {
+            found = true;
             return false;
+        }
         return true;
     };
 
@@ -440,6 +474,11 @@ const failable<bool> del(const value& key, const TinyCDB& cdb) {
 
     // Rewrite the db
     const failable<bool> r = rewrite(update, finish, cdb);
+    if (!hasContent(r) || !found) {
+        ostringstream os;
+        os << "Couldn't delete tinycdb entry: " << key;
+        return hasContent(r)? mkfailure<bool>(str(os), 404, false) : r;
+    }
     debug(r, "tinycdb::delete::result");
     return r;
 }