planner_multi: add update functionality

Problem: when updating the Fluxion resource graph planners, resources,
counts, and their orders can be changed by mutation of the resource
graph topology and attributes.

Add `update` functionality to `planner_multi` and the C interface to add
new resources and planners, reorder, modify, and permute existing
resources, and delete removed resources.

Author: milroy

resource/planner/c++/planner_multi.cpp

@@ -182,6 +182,48 @@ planner_multi::~planner_multi ()
     erase ();
 }
 
+void planner_multi::add_planner (int64_t base_time, uint64_t duration,
+                                 const uint64_t resource_total,
+                                 const char *resource_type, size_t i)
+{
+    std::string type;
+    planner_t *p = nullptr;
+
+    try {
+        type = std::string (resource_type);
+        p = new planner_t (base_time, duration,
+                           resource_total,
+                           resource_type);
+    } catch (std::bad_alloc &e) {
+        errno = ENOMEM;
+        throw std::bad_alloc ();
+    }
+    m_iter.counts[type] = 0;
+    if (i > m_types_totals_planners.size ())
+        m_types_totals_planners.push_back ({type, resource_total, p});
+    else {
+        auto it = m_types_totals_planners.begin () + i;
+        m_types_totals_planners.insert (
+                        it, planner_multi_meta{type, resource_total, p});
+    }
+    
+}
+
+void planner_multi::delete_planners (const std::unordered_set<std::string> &rtypes)
+{
+    auto &by_res = m_types_totals_planners.get<res_type> ();
+    for (auto iter = by_res.begin (); iter != by_res.end ();) {
+        if (rtypes.find (iter->resource_type) == rtypes.end ()) {
+            // need to remove from request_multi
+            m_iter.counts.erase (iter->resource_type);
+            // Trigger planner destructor
+            delete iter->planner;
+            iter = by_res.erase (iter);
+        } else
+            ++iter;
+    }
+}
+
 planner_t *planner_multi::get_planner_at (size_t i) const
 {
     return m_types_totals_planners.at (i).planner;
@@ -193,6 +235,32 @@ planner_t *planner_multi::get_planner_at (const char *type) const
     return by_res.find (std::string (type))->planner;
 }
 
+void planner_multi::update_planner_index (const char *type, size_t i)
+{
+    std::string rtype = std::string (type);
+    auto by_res = m_types_totals_planners.get<res_type> ().find (rtype);
+    auto new_idx = m_types_totals_planners.begin () + i;
+    auto curr_idx = m_types_totals_planners.get<idx> ().iterator_to (*by_res);
+    // noop if new_idx == curr_idx
+    m_types_totals_planners.relocate (new_idx, curr_idx);
+}
+
+int planner_multi::update_planner_total (uint64_t total, size_t i)
+{
+    m_types_totals_planners.at (i).resource_total = total;
+    return m_types_totals_planners.at (i).planner->plan->update_total (total);
+}
+
+bool planner_multi::planner_at (const char *type) const
+{
+    auto &by_res = m_types_totals_planners.get<res_type> ();
+    auto result = by_res.find (std::string (type));
+    if (result == by_res.end ())
+        return false;
+    else
+        return true;
+}
+
 size_t planner_multi::get_planners_size () const
 {
     return m_types_totals_planners.size ();

resource/planner/c++/planner_multi.hpp

@@ -13,6 +13,7 @@
 
 #include "planner.hpp"
 #include <unordered_map>
+#include <unordered_set>
 #include <boost/multi_index_container.hpp>
 #include <boost/multi_index/member.hpp>
 #include <boost/multi_index/random_access_index.hpp>
@@ -65,6 +66,9 @@ class planner_multi {
     // Public getters and setters
     planner_t *get_planner_at (size_t i) const;
     planner_t *get_planner_at (const char *type) const;
+    void update_planner_index (const char *type, size_t i);
+    int update_planner_total (uint64_t total, size_t i);
+    bool planner_at (const char *type) const;
     size_t get_planners_size () const;
     int64_t get_resource_total_at (size_t i) const;
     int64_t get_resource_total_at (const char *type) const;
@@ -81,6 +85,12 @@ class planner_multi {
     uint64_t get_span_counter ();
     void set_span_counter (uint64_t sc);
     void incr_span_counter ();
+    void add_planner (int64_t base_time, uint64_t duration,
+                      const uint64_t resource_total,
+                      const char *resource_type, size_t i);
+    // Assuming small number of resources,
+    // could try set, too
+    void delete_planners (const std::unordered_set<std::string> &rtypes);
 
 private:
     multi_container m_types_totals_planners;

resource/planner/c/planner_multi.h

@@ -292,6 +292,28 @@ size_t planner_multi_span_size (planner_multi_t *ctx);
 */
 bool planner_multis_equal (planner_multi_t *lhs, planner_multi_t *rhs);
 
+/*! Update the counts and resource types to support elasticity.
+ *
+ *  \param ctx          opaque multi-planner context returned
+ *                      from planner_multi_new.
+ *  \param resource_totals
+ *                      64-bit unsigned integer array of size len where each
+ *                      element contains the total count of available resources
+ *                      of a single resource type.
+ *  \param resource_types
+ *                      string array of size len where each element contains
+ *                      the resource type corresponding to each corresponding
+ *                      element in the resource_totals array.
+ *  \param len          length of resource_counts and resource_types arrays.
+ *  \return             0 on success; -1 on an error with errno set as follows:
+ *                          EINVAL: invalid argument.
+ */
+int planner_multi_update (planner_multi_t *ctx,
+                          const uint64_t *resource_totals,
+                          const char **resource_types,
+                          size_t len);
+
+
 #ifdef __cplusplus
 }
 #endif

resource/planner/c/planner_multi_c_interface.cpp

@@ -14,6 +14,7 @@
 #include <limits>
 #include <vector>
 #include <map>
+#include <unordered_set>
 
 #include "planner_multi.h"
 #include "resource/planner/c++/planner_multi.hpp"
@@ -466,6 +467,63 @@ extern "C" bool planner_multis_equal (planner_multi_t *lhs,
     return (*(lhs->plan_multi) == *(rhs->plan_multi));
 }
 
+extern "C" int planner_multi_update (planner_multi_t *ctx,
+                                     const uint64_t *resource_totals,
+                                     const char **resource_types,
+                                     size_t len)
+{
+    int rc = -1;
+    size_t i = 0;
+    // Assuming small number of resource types,
+    // could try set, too
+    std::unordered_set<std::string> rtypes;
+    int64_t base_time = 0;
+    int64_t duration = 0;
+
+    if (!ctx || !resource_totals || !resource_types) {
+        errno = EINVAL;
+        goto done;
+    }
+    base_time = planner_base_time (
+                    ctx->plan_multi->get_planner_at (static_cast<size_t> (0)));
+    duration = planner_duration (
+                    ctx->plan_multi->get_planner_at (static_cast<size_t> (0)));
+    if (duration < 0) {
+        errno = EINVAL;
+        goto done;
+    }
+
+    for (i = 0; i < len; ++i) {
+        if (resource_totals[i] >
+              static_cast<uint64_t> (std::numeric_limits<int64_t>::max ())) {
+                errno = ERANGE;
+                goto done;
+        }
+        rtypes.insert (resource_types[i]);
+        if (!ctx->plan_multi->planner_at (resource_types[i])) {
+            // Assume base_time same as parent
+            ctx->plan_multi->add_planner (base_time, static_cast<uint64_t> (duration),
+                                          resource_totals[i], resource_types[i], i);
+        } else {
+            // Index could have changed
+            ctx->plan_multi->update_planner_index (resource_types[i], i);
+            if ( (rc = ctx->plan_multi->update_planner_total (resource_totals[i],
+                                                              i)) != 0) {
+                errno = EINVAL;
+                goto done;
+            }
+        }
+    }
+    // remove values not in new types
+    if (rtypes.size () > 0)
+        ctx->plan_multi->delete_planners (rtypes);
+
+    rc = 0;
+
+done:
+    return rc;
+}
+
 /*
  * vi: ts=4 sw=4 expandtab
  */