nserver/ -> ./

1 files changed, 310 insertions, 0 deletions

diff --git a/src/protocol.c b/src/protocol.c
new file mode 100644
index 0000000..77b806a
--- /dev/null
+++ b/src/protocol.c
@@ -0,0 +1,310 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright © 2020 rsiddharth <s@ricketyspace.net>
+ */
+
+#include <protocol.h>
+
+static TSTree *tst;
+
+int sscreate(char *key)
+{
+    check(key != NULL || strlen(key) < 1, "key invalid");
+
+    // 1. Check if key is already in the tree.
+    Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+
+    // If it's already there; there's nothing to do.
+    if (rec != NULL && rec->deleted == 0) {
+        return 1;
+    }
+    // If it's already there and deleted, undelete it.
+    if (rec != NULL && rec->deleted == 1) {
+        rec->deleted = 0;
+
+        // Allocate fresh Stats.
+        rec->st = Stats_create();
+        check(rec->st != NULL, "stats creation failed");
+
+        return 2;
+    }
+
+    // 2. Create bstring from 'key'.
+    bstring k = bfromcstr(key);
+    check(k != NULL, "key creation failed");
+
+    // 3. Allocate fresh Stats.
+    Stats *st = Stats_create();
+    check(st != NULL, "stats creation failed");
+
+    // 4. Create Record.
+    rec = (Record *) calloc(1, sizeof(Record));
+    check_mem(rec);
+
+    // 5. Initialize Record.
+    rec->key = k;
+    rec->st = st;
+    rec->deleted = 0;
+
+    // 6. Add Record to tree.
+    tst = TSTree_insert(tst, key, strlen(key), rec);
+    check(tst != NULL, "tstree insert failed");
+
+    return 0;
+ error:
+    return -1;
+}
+
+int ssdelete(char *key)
+{
+   check(key != NULL || strlen(key) < 1, "key invalid");
+   check(tst != NULL, "tstree not initialized");
+
+   Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+   if (rec == NULL) {
+       // key does not exists.
+       return 0;
+   }
+
+   // Mark as deleted.
+   rec->deleted = 1;
+
+   // Free Stats.
+   free(rec->st);
+
+   return 0;
+ error:
+   return -1;
+}
+
+int sssample_parent(char *key, double s)
+{
+    check(key != NULL || strlen(key) < 1, "key invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. Try to get Record with key prefix.
+    Record *rec = (Record *) TSTree_search_prefix(tst, key, strlen(key));
+
+    if (rec == NULL) {
+        // No record with key prefix.
+        return 0;
+    }
+    check(rec->st != NULL, "record's st invalid");
+
+    if (rec->deleted == 1) {
+        // Record was deleted; nop.
+        return 0;
+    }
+
+    // 2. Sample!
+    Stats_sample(rec->st, s);
+
+    return 1;
+ error:
+    return -1;
+}
+
+double sssample(char *key, double s)
+{
+    check(key != NULL || strlen(key) < 1, "key invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. Try to get Record for key.
+    Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+
+    check(rec != NULL, "record not found");
+    check(rec->st != NULL, "record's st invalid");
+    check(rec->deleted != 1, "record was deleted");
+
+    // 2. Sample!
+    Stats_sample(rec->st, s);
+
+    // 3. Sample parent!
+    int rc = sssample_parent(key, s);
+    check(rc >= 0, "sampling parent failed");
+
+    // 4. Get mean.
+    double m = Stats_mean(rec->st);
+
+    return m;
+ error:
+    return -1;
+}
+
+double ssmean(char *key)
+{
+    check(key != NULL || strlen(key) < 1, "key invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. Try to get Record for key.
+    Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+
+    check(rec != NULL, "record not found");
+    check(rec->deleted != 1, "record was deleted");
+    check(rec->st != NULL, "record's st invalid");
+
+    // 2. Get mean.
+    double m = Stats_mean(rec->st);
+
+    return m;
+ error:
+    return -1;
+}
+
+char *ssdump(char *key)
+{
+    check(key != NULL && strlen(key) > 0, "key invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. create bstring from 'key'.
+    Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+
+    check(rec != NULL, "record not found");
+    check(rec->st != NULL, "stats not found for key");
+    check(rec->deleted != 1, "record was deleted");
+
+    // 2. get dump.
+    char *dstr = Stats_dump(rec->st);
+    check(dstr != NULL, "dump failed for key");
+
+    return dstr;
+ error:
+    return NULL;
+}
+
+// meant to be used by sslist.
+void traverse_tree(void *value, void *data)
+{
+    Record *rec  = (Record *) value;
+    bstring bstr = (bstring) data;
+
+    check(rec != NULL, "Record is NULL");
+    check(rec->deleted != 1, "Record was deleted");
+    check(bstr != NULL, "bstr is NULL");
+    check(rec->key != NULL, "Record's key is NULL");
+    check(blength(rec->key) > 0, "Record's key is an empty string");
+
+    int rc = bconcat(bstr, rec->key);
+    check(rc == BSTR_OK, "bstr key concat failed");
+
+    rc = bconchar(bstr, '\n');
+    check(rc == BSTR_OK, "bstr newline concat failed");
+
+ error:
+    return;
+}
+
+
+char *sslist()
+{
+    char *list = NULL, *tmp = NULL;
+
+    if (tst == NULL) {
+        list = (char *) calloc(7 + 1, sizeof(char));
+        check_mem(list);
+
+        list = strncpy(list, "EMPTY\n\r", 7);
+
+        return list;
+    }
+
+    // 1. Create "accumulator" string.
+    bstring ks_str = bfromcstr("");
+    check(ks_str != NULL, "error creating keys_str");
+
+    // 2. Accumulate keys into "accumulator" string.
+    TSTree_traverse(tst, traverse_tree, ks_str);
+
+    // 3. Make result.
+    tmp = bstr2cstr(ks_str, ' ');
+
+    list = (char *) calloc(strlen(tmp) + 1, sizeof(char));
+    check_mem(list);
+
+    list = strncpy(list, tmp, strlen(tmp));
+
+    // 4. Clean up.
+    bcstrfree(tmp);
+
+    // 3. Return result.
+    return list;
+ error:
+    if (tmp) {
+        bcstrfree(tmp);
+    }
+    return NULL;
+}
+
+int ssstore(char *key)
+{
+    check(key != NULL && strlen(key) > 0, "key invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. create bstring from 'key'.
+    Record *rec = (Record *) TSTree_search(tst, key, strlen(key));
+
+    check(rec != NULL, "record not found");
+    check(rec->st != NULL, "stats not found for key");
+    check(rec->deleted != 1, "record was deleted");
+
+    // 2. stringify the stats.
+    char *st_str = Stats_stringify(rec->st);
+    check(st_str != NULL, "stats stringify failed");
+
+    // 3. store stats in db.
+    int rc = db_store(key, st_str);
+    check(rc == 0, "db store failed");
+
+    return 0;
+ error:
+    return -1;
+}
+
+int ssload(char *from, char *to)
+{
+    check(from != NULL && strlen(from) > 0, "from invalid");
+    check(to != NULL && strlen(to) > 0, "to invalid");
+    check(tst != NULL, "tstree not initialized");
+
+    // 1. Check if 'to' key already exists.
+    Record *rec = (Record *) TSTree_search(tst, to, strlen(to));
+
+    // 2. if 'to' key exists return immediately with -2.
+    if (rec != NULL && rec->deleted == 0) {
+        return -2;
+    }
+
+    // 3. read 'from' key from database.
+    char *st_str = db_load(from);
+    check(st_str != NULL, "db load failed");
+
+    // 4. construct stats from string.
+    Stats *st = Stats_unstringify(st_str);
+    check(st != NULL, "stats unstringify failed");
+
+    // 5. create Record if needed.
+    int rec_created =  0;
+    if (rec == NULL)  {
+        rec = (Record *) calloc(1, sizeof(Record));
+        check_mem(rec);
+        rec_created = 1;
+    }
+
+    // 6. get things ready for insertiion
+    bstring tk = bfromcstr(to);
+    check(tk != NULL, "key creation failed");
+
+    rec->key = tk;
+    rec->st = st;
+    rec->deleted = 0;
+
+    // 7. insert Record into 'to' key in the TSTree if needed.
+    if (rec_created == 1) {
+        tst = TSTree_insert(tst, to, strlen(to), rec);
+        check(tst != NULL, "tstree insert failed");
+    }
+
+    return 0;
+ error:
+    return -1;
+}