2017-03-02 14:05:42 +02:00

1041 lines
27 KiB
C

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2019-07-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
/**
* @file avro_schema.c - Avro schema related functions
*/
#include "avrorouter.h"
#include <maxscale/mysql_utils.h>
#include <jansson.h>
#include <stdio.h>
#include <limits.h>
#include <unistd.h>
#include <maxscale/log_manager.h>
#include <sys/stat.h>
#include <errno.h>
#include <maxscale/debug.h>
#include <string.h>
#include <strings.h>
#include <maxscale/alloc.h>
/**
* @brief Convert the MySQL column type to a compatible Avro type
*
* Some fields are larger than they need to be but since the Avro integer
* compression is quite efficient, the real loss in performance is negligible.
* @param type MySQL column type
* @return String representation of the Avro type
*/
static const char* column_type_to_avro_type(uint8_t type)
{
switch (type)
{
case TABLE_COL_TYPE_TINY:
case TABLE_COL_TYPE_SHORT:
case TABLE_COL_TYPE_LONG:
case TABLE_COL_TYPE_INT24:
case TABLE_COL_TYPE_BIT:
return "int";
case TABLE_COL_TYPE_FLOAT:
return "float";
case TABLE_COL_TYPE_DOUBLE:
case TABLE_COL_TYPE_NEWDECIMAL:
return "double";
case TABLE_COL_TYPE_NULL:
return "null";
case TABLE_COL_TYPE_LONGLONG:
return "long";
case TABLE_COL_TYPE_TINY_BLOB:
case TABLE_COL_TYPE_MEDIUM_BLOB:
case TABLE_COL_TYPE_LONG_BLOB:
case TABLE_COL_TYPE_BLOB:
return "bytes";
default:
return "string";
}
}
/**
* @brief Create a new JSON Avro schema from the table map and create table abstractions
*
* The schema will always have a GTID field and all records contain the current
* GTID of the transaction.
* @param map TABLE_MAP for this table
* @param create The TABLE_CREATE for this table
* @return New schema or NULL if an error occurred
*/
char* json_new_schema_from_table(TABLE_MAP *map)
{
TABLE_CREATE *create = map->table_create;
if (map->version != create->version)
{
MXS_ERROR("Version mismatch for table %s.%s. Table map version is %d and "
"the table definition version is %d.", map->database, map->table,
map->version, create->version);
return NULL;
}
json_error_t err;
memset(&err, 0, sizeof(err));
json_t *schema = json_object();
json_object_set_new(schema, "namespace", json_string("MaxScaleChangeDataSchema.avro"));
json_object_set_new(schema, "type", json_string("record"));
json_object_set_new(schema, "name", json_string("ChangeRecord"));
json_t *array = json_array();
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
avro_domain, "type", "int"));
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
avro_server_id, "type", "int"));
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
avro_sequence, "type", "int"));
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
avro_event_number, "type", "int"));
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
avro_timestamp, "type", "int"));
/** Enums and other complex types are defined with complete JSON objects
* instead of string values */
json_t *event_types = json_pack_ex(&err, 0, "{s:s, s:s, s:[s,s,s,s]}", "type", "enum",
"name", "EVENT_TYPES", "symbols", "insert",
"update_before", "update_after", "delete");
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:o}", "name", avro_event_type,
"type", event_types));
for (uint64_t i = 0; i < map->columns; i++)
{
json_array_append(array, json_pack_ex(&err, 0, "{s:s, s:s}", "name",
create->column_names[i], "type",
column_type_to_avro_type(map->column_types[i])));
}
json_object_set_new(schema, "fields", array);
char* rval = json_dumps(schema, JSON_PRESERVE_ORDER);
json_decref(schema);
return rval;
}
/**
* @brief Check whether the field is one that was generated by the avrorouter
*
* @param name Name of the field in the Avro schema
* @return True if field was not generated by the avrorouter
*/
static inline bool not_generated_field(const char* name)
{
return strcmp(name, avro_domain) && strcmp(name, avro_server_id) &&
strcmp(name, avro_sequence) && strcmp(name, avro_event_number) &&
strcmp(name, avro_event_type) && strcmp(name, avro_timestamp);
}
/**
* @brief Extract the field names from a JSON Avro schema file
*
* This function extracts the names of the columns from the JSON format Avro
* schema in the file @c filename. This function assumes that the field definitions
* in @c filename are in the same order as they are in the CREATE TABLE statement.
*
* @param filename The Avro schema in JSON format
* @param table The TABLE_CREATE object to populate
* @return True on success successfully, false on error
*/
bool json_extract_field_names(const char* filename, TABLE_CREATE *table)
{
bool rval = false;
json_error_t err;
err.text[0] = '\0';
json_t *obj, *arr;
if ((obj = json_load_file(filename, 0, &err)) && (arr = json_object_get(obj, "fields")))
{
ss_dassert(json_is_array(arr));
if (json_is_array(arr))
{
int array_size = json_array_size(arr);
table->column_names = (char**)MXS_MALLOC(sizeof(char*) * (array_size));
if (table->column_names)
{
int columns = 0;
rval = true;
for (int i = 0; i < array_size; i++)
{
json_t* val = json_array_get(arr, i);
if (json_is_object(val))
{
json_t *name = json_object_get(val, "name");
if (name && json_is_string(name))
{
const char *name_str = json_string_value(name);
if (not_generated_field(name_str))
{
table->column_names[columns++] = MXS_STRDUP_A(name_str);
}
}
else
{
MXS_ERROR("JSON value for \"name\" was not a string in "
"file '%s'.", filename);
rval = false;
}
}
else
{
MXS_ERROR("JSON value for \"fields\" was not an array of objects in "
"file '%s'.", filename);
rval = false;
}
}
table->columns = columns;
}
}
else
{
MXS_ERROR("JSON value for \"fields\" was not an array in file '%s'.", filename);
}
json_decref(obj);
}
else
{
MXS_ERROR("Failed to load JSON from file '%s': %s", filename,
obj && !arr ? "No 'fields' value in object." : err.text);
}
return rval;
}
/**
* @brief Save the Avro schema of a table to disk
*
* @param path Schema directory
* @param schema Schema in JSON format
* @param map Table map that @p schema represents
*/
void save_avro_schema(const char *path, const char* schema, TABLE_MAP *map)
{
char filepath[PATH_MAX];
snprintf(filepath, sizeof(filepath), "%s/%s.%s.%06d.avsc", path, map->database,
map->table, map->version);
if (access(filepath, F_OK) != 0)
{
if (!map->table_create->was_used)
{
FILE *file = fopen(filepath, "wb");
if (file)
{
fprintf(file, "%s\n", schema);
map->table_create->was_used = true;
fclose(file);
}
}
}
else
{
MXS_NOTICE("Schema version %d already exists: %s", map->version, filepath);
}
}
/**
* Extract the table definition from a CREATE TABLE statement
* @param sql The SQL statement
* @param size Length of the statement
* @return Pointer to the start of the definition of NULL if the query is
* malformed.
*/
static const char* get_table_definition(const char *sql, int* size)
{
const char *rval = NULL;
const char *ptr = sql;
const char *end = strchr(sql, '\0');
while (ptr < end && *ptr != '(')
{
ptr++;
}
/** We assume at least the parentheses are in the statement */
if (ptr < end - 2)
{
int depth = 0;
ptr++;
const char *start = ptr; // Skip first parenthesis
while (ptr < end)
{
switch (*ptr)
{
case '(':
depth++;
break;
case ')':
depth--;
break;
default:
break;
}
/** We found the last closing parenthesis */
if (depth < 0)
{
*size = ptr - start;
rval = start;
break;
}
ptr++;
}
}
return rval;
}
/**
* Extract the table name from a CREATE TABLE statement
* @param sql SQL statement
* @param dest Destination where the table name is extracted. Must be at least
* MYSQL_TABLE_MAXLEN bytes long.
* @return True if extraction was successful
*/
static bool get_table_name(const char* sql, char* dest)
{
bool rval = false;
const char* ptr = strchr(sql, '(');
if (ptr)
{
ptr--;
while (*ptr == '`' || isspace(*ptr))
{
ptr--;
}
const char* end = ptr + 1;
while (*ptr != '`' && *ptr != '.' && !isspace(*ptr))
{
ptr--;
}
ptr++;
memcpy(dest, ptr, end - ptr);
dest[end - ptr] = '\0';
rval = true;
}
return rval;
}
/**
* Extract the database name from a CREATE TABLE statement
* @param sql SQL statement
* @param dest Destination where the database name is extracted. Must be at least
* MYSQL_DATABASE_MAXLEN bytes long.
* @return True if extraction was successful
*/
static bool get_database_name(const char* sql, char* dest)
{
bool rval = false;
const char* ptr = strchr(sql, '(');
if (ptr)
{
ptr--;
while (*ptr == '`' || isspace(*ptr))
{
ptr--;
}
while (*ptr != '`' && *ptr != '.' && !isspace(*ptr))
{
ptr--;
}
while (*ptr == '`' || *ptr == '.' || isspace(*ptr))
{
ptr--;
}
const char* end = ptr + 1;
while (*ptr != '`' && *ptr != '.' && !isspace(*ptr))
{
ptr--;
}
ptr++;
memcpy(dest, ptr, end - ptr);
dest[end - ptr] = '\0';
rval = true;
}
return rval;
}
void make_valid_avro_identifier(char* ptr)
{
while (*ptr)
{
if (!isalnum(*ptr) && *ptr != '_')
{
*ptr = '_';
}
ptr++;
}
}
const char* next_field_definition(const char* ptr)
{
int depth = 0;
bool quoted = false;
char qchar;
while (*ptr)
{
if (!quoted)
{
if (*ptr == '(')
{
depth++;
}
else if (*ptr == ')')
{
depth--;
}
else if (*ptr == '"' || *ptr == '\'')
{
qchar = *ptr;
quoted = true;
}
else if (*ptr == ',' && depth == 0 && !quoted)
{
ptr++;
break;
}
}
else if (qchar == *ptr)
{
quoted = false;
}
ptr++;
}
return ptr;
}
static const char *extract_field_name(const char* ptr, char* dest, size_t size)
{
bool bt = false;
while (*ptr && (isspace(*ptr) || (bt = *ptr == '`')))
{
ptr++;
if (bt)
{
break;
}
}
if (strncasecmp(ptr, "constraint", 10) == 0 || strncasecmp(ptr, "index", 5) == 0 ||
strncasecmp(ptr, "key", 3) == 0 || strncasecmp(ptr, "fulltext", 8) == 0 ||
strncasecmp(ptr, "spatial", 7) == 0 || strncasecmp(ptr, "foreign", 7) == 0 ||
strncasecmp(ptr, "unique", 6) == 0 || strncasecmp(ptr, "primary", 7) == 0)
{
return NULL;
}
const char *start = ptr;
if (!bt)
{
while (*ptr && !isspace(*ptr))
{
ptr++;
}
}
else
{
while (*ptr && *ptr != '`')
{
ptr++;
}
}
if (ptr > start)
{
/** Valid identifier */
size_t bytes = ptr - start;
memcpy(dest, start, bytes);
dest[bytes] = '\0';
make_valid_avro_identifier(dest);
ptr = next_field_definition(ptr);
}
else
{
ptr = NULL;
}
return ptr;
}
/**
* Process a table definition into an array of column names
* @param nameptr table definition
* @return Number of processed columns or -1 on error
*/
static int process_column_definition(const char *nameptr, char*** dest)
{
/** Process columns in groups of 8 */
size_t chunks = 1;
const size_t chunk_size = 8;
int i = 0;
char **names = MXS_MALLOC(sizeof(char*) * (chunks * chunk_size + 1));
if (names == NULL)
{
return -1;
}
char colname[512];
while ((nameptr = extract_field_name(nameptr, colname, sizeof(colname))))
{
if (i >= chunks * chunk_size)
{
char **tmp = MXS_REALLOC(names, (++chunks * chunk_size + 1) * sizeof(char*));
if (tmp == NULL)
{
for (int x = 0; x < i; x++)
{
MXS_FREE(names[x]);
}
MXS_FREE(names);
return -1;
}
names = tmp;
}
if ((names[i++] = MXS_STRDUP(colname)) == NULL)
{
for (int x = 0; x < i; x++)
{
MXS_FREE(names[x]);
}
MXS_FREE(names);
return -1;
}
}
*dest = names;
return i;
}
TABLE_CREATE* table_create_from_schema(const char* file, const char* db,
const char* table, int version)
{
db = MXS_STRDUP(db);
table = MXS_STRDUP(table);
TABLE_CREATE* newtable = (TABLE_CREATE*)MXS_MALLOC(sizeof(TABLE_CREATE));
if (!db || !table || !newtable)
{
MXS_FREE((void*)db);
MXS_FREE((void*)table);
MXS_FREE(newtable);
return NULL;
}
newtable->table = (char*)table;
newtable->database = (char*)db;
newtable->version = version;
newtable->was_used = true;
if (!json_extract_field_names(file, newtable))
{
MXS_FREE(newtable->table);
MXS_FREE(newtable->database);
MXS_FREE(newtable);
newtable = NULL;
}
return newtable;
}
/**
* @brief Handle a query event which contains a CREATE TABLE statement
* @param sql Query SQL
* @param db Database where this query was executed
* @return New CREATE_TABLE object or NULL if an error occurred
*/
TABLE_CREATE* table_create_alloc(const char* sql, const char* event_db)
{
/** Extract the table definition so we can get the column names from it */
int stmt_len = 0;
const char* statement_sql = get_table_definition(sql, &stmt_len);
ss_dassert(statement_sql);
char table[MYSQL_TABLE_MAXLEN + 1];
char database[MYSQL_DATABASE_MAXLEN + 1];
const char *db = event_db;
MXS_DEBUG("Create table statement: %.*s", stmt_len, statement_sql);
if (!get_table_name(sql, table))
{
MXS_ERROR("Malformed CREATE TABLE statement, could not extract table name: %s", sql);
return NULL;
}
/** The CREATE statement contains the database name */
if (strlen(db) == 0)
{
if (!get_database_name(sql, database))
{
MXS_ERROR("Malformed CREATE TABLE statement, could not extract "
"database name: %s", sql);
return NULL;
}
db = database;
}
char **names = NULL;
int n_columns = process_column_definition(statement_sql, &names);
ss_dassert(n_columns > 0);
/** We have appear to have a valid CREATE TABLE statement */
TABLE_CREATE *rval = NULL;
if (n_columns > 0)
{
if ((rval = MXS_MALLOC(sizeof(TABLE_CREATE))))
{
rval->version = 1;
rval->was_used = false;
rval->column_names = names;
rval->columns = n_columns;
rval->database = MXS_STRDUP(db);
rval->table = MXS_STRDUP(table);
}
if (rval == NULL || rval->database == NULL || rval->table == NULL)
{
if (rval)
{
MXS_FREE(rval->database);
MXS_FREE(rval->table);
MXS_FREE(rval);
}
for (int i = 0; i < n_columns; i++)
{
MXS_FREE(names[i]);
}
MXS_FREE(names);
rval = NULL;
}
}
else
{
MXS_ERROR("No columns in a CREATE TABLE statement: %.*s", stmt_len, statement_sql);
}
return rval;
}
/**
* Free a TABLE_CREATE structure
* @param value Value to free
*/
void table_create_free(TABLE_CREATE* value)
{
if (value)
{
for (uint64_t i = 0; i < value->columns; i++)
{
MXS_FREE(value->column_names[i]);
}
MXS_FREE(value->column_names);
MXS_FREE(value->table);
MXS_FREE(value->database);
MXS_FREE(value);
}
}
static const char* get_next_def(const char* sql, const char* end)
{
int depth = 0;
while (sql < end)
{
if (*sql == ',' && depth == 0)
{
return sql + 1;
}
else if (*sql == '(')
{
depth++;
}
else if (*sql == ')')
{
depth--;
}
sql++;
}
return NULL;
}
static const char* get_tok(const char* sql, int* toklen, const char* end)
{
const char *start = sql;
while (isspace(*start))
{
start++;
}
int len = 0;
int depth = 0;
while (start + len < end)
{
if (isspace(start[len]) && depth == 0)
{
*toklen = len;
return start;
}
else if (start[len] == '(')
{
depth++;
}
else if (start[len] == ')')
{
depth--;
}
len++;
}
if (len > 0 && start + len <= end)
{
*toklen = len;
return start;
}
return NULL;
}
static bool tok_eq(const char *a, const char *b, size_t len)
{
size_t i = 0;
while (i < len)
{
if (tolower(a[i]) - tolower(b[i]) != 0)
{
return false;
}
i++;
}
return true;
}
void read_alter_identifier(const char *sql, const char *end, char *dest, int size)
{
int len = 0;
const char *tok = get_tok(sql, &len, end);
if (tok && (tok = get_tok(tok + len, &len, end)) && (tok = get_tok(tok + len, &len, end)))
{
snprintf(dest, size, "%.*s", len, tok);
}
}
void make_avro_token(char* dest, const char* src, int length)
{
while (*src == '(' || *src == ')' || *src == '`' || isspace(*src))
{
src++;
length--;
}
const char *end = src;
for (int i = 0; i < length; i++)
{
if (end[i] == '(' || end[i] == ')' || end[i] == '`' || isspace(end[i]))
{
length = i;
break;
}
}
memcpy(dest, src, length);
dest[length] = '\0';
}
bool table_create_alter(TABLE_CREATE *create, const char *sql, const char *end)
{
const char *tbl = strcasestr(sql, "table"), *def;
if ((def = strchr(tbl, ' ')))
{
int len = 0;
const char *tok = get_tok(def, &len, end);
if (tok)
{
MXS_DEBUG("Altering table %.*s\n", len, tok);
def = tok + len;
}
int updates = 0;
while (tok && (tok = get_tok(tok + len, &len, end)))
{
const char *ptok = tok;
int plen = len;
tok = get_tok(tok + len, &len, end);
if (tok)
{
if (tok_eq(ptok, "add", plen) && tok_eq(tok, "column", len))
{
tok = get_tok(tok + len, &len, end);
char ** tmp = MXS_REALLOC(create->column_names, sizeof(char*) * create->columns + 1);
ss_dassert(tmp);
if (tmp == NULL)
{
return false;
}
create->column_names = tmp;
char avro_token[len + 1];
make_avro_token(avro_token, tok, len);
create->column_names[create->columns] = MXS_STRDUP_A(avro_token);
create->columns++;
updates++;
tok = get_next_def(tok, end);
len = 0;
}
else if (tok_eq(ptok, "drop", plen) && tok_eq(tok, "column", len))
{
tok = get_tok(tok + len, &len, end);
MXS_FREE(create->column_names[create->columns - 1]);
char ** tmp = MXS_REALLOC(create->column_names, sizeof(char*) * create->columns - 1);
ss_dassert(tmp);
if (tmp == NULL)
{
return false;
}
create->column_names = tmp;
create->columns--;
updates++;
tok = get_next_def(tok, end);
len = 0;
}
else if (tok_eq(ptok, "change", plen) && tok_eq(tok, "column", len))
{
tok = get_tok(tok + len, &len, end);
MXS_FREE(create->column_names[create->columns - 1]);
create->column_names[create->columns - 1] = strndup(tok, len);
updates++;
tok = get_next_def(tok, end);
len = 0;
}
}
else
{
break;
}
}
/** Only increment the create version if it has an associated .avro
* file. The .avro file is only created if it is acutally used. */
if (updates > 0 && create->was_used)
{
create->version++;
create->was_used = false;
}
}
return true;
}
/**
* @brief Read the fully qualified name of the table
*
* @param ptr Pointer to the start of the event payload
* @param post_header_len Length of the event specific header, 8 or 6 bytes
* @param dest Destination where the string is stored
* @param len Size of destination
*/
void read_table_info(uint8_t *ptr, uint8_t post_header_len, uint64_t *tbl_id, char* dest, size_t len)
{
uint64_t table_id = 0;
size_t id_size = post_header_len == 6 ? 4 : 6;
memcpy(&table_id, ptr, id_size);
ptr += id_size;
uint16_t flags = 0;
memcpy(&flags, ptr, 2);
ptr += 2;
uint8_t schema_name_len = *ptr++;
char schema_name[schema_name_len + 2];
/** Copy the NULL byte after the schema name */
memcpy(schema_name, ptr, schema_name_len + 1);
ptr += schema_name_len + 1;
uint8_t table_name_len = *ptr++;
char table_name[table_name_len + 2];
/** Copy the NULL byte after the table name */
memcpy(table_name, ptr, table_name_len + 1);
snprintf(dest, len, "%s.%s", schema_name, table_name);
*tbl_id = table_id;
}
/**
* @brief Extract a table map from a table map event
*
* This assumes that the complete event minus the replication header is stored
* at @p ptr
* @param ptr Pointer to the start of the event payload
* @param post_header_len Length of the event specific header, 8 or 6 bytes
* @return New TABLE_MAP or NULL if memory allocation failed
*/
TABLE_MAP *table_map_alloc(uint8_t *ptr, uint8_t hdr_len, TABLE_CREATE* create)
{
uint64_t table_id = 0;
size_t id_size = hdr_len == 6 ? 4 : 6;
memcpy(&table_id, ptr, id_size);
ptr += id_size;
uint16_t flags = 0;
memcpy(&flags, ptr, 2);
ptr += 2;
uint8_t schema_name_len = *ptr++;
char schema_name[schema_name_len + 2];
/** Copy the NULL byte after the schema name */
memcpy(schema_name, ptr, schema_name_len + 1);
ptr += schema_name_len + 1;
uint8_t table_name_len = *ptr++;
char table_name[table_name_len + 2];
/** Copy the NULL byte after the table name */
memcpy(table_name, ptr, table_name_len + 1);
ptr += table_name_len + 1;
uint64_t column_count = mxs_leint_value(ptr);
ptr += mxs_leint_bytes(ptr);
/** Column types */
uint8_t *column_types = ptr;
ptr += column_count;
size_t metadata_size = 0;
uint8_t* metadata = (uint8_t*)mxs_lestr_consume(&ptr, &metadata_size);
uint8_t *nullmap = ptr;
size_t nullmap_size = (column_count + 7) / 8;
TABLE_MAP *map = MXS_MALLOC(sizeof(TABLE_MAP));
if (map)
{
map->id = table_id;
map->version = create->version;
map->flags = flags;
ss_dassert(column_count == create->columns);
map->columns = column_count;
map->column_types = MXS_MALLOC(column_count);
/** Allocate at least one byte for the metadata */
map->column_metadata = MXS_CALLOC(1, metadata_size + 1);
map->column_metadata_size = metadata_size;
map->null_bitmap = MXS_MALLOC(nullmap_size);
map->database = MXS_STRDUP(schema_name);
map->table = MXS_STRDUP(table_name);
map->table_create = create;
if (map->column_types && map->database && map->table &&
map->column_metadata && map->null_bitmap)
{
memcpy(map->column_types, column_types, column_count);
memcpy(map->null_bitmap, nullmap, nullmap_size);
memcpy(map->column_metadata, metadata, metadata_size);
}
else
{
MXS_FREE(map->null_bitmap);
MXS_FREE(map->column_metadata);
MXS_FREE(map->column_types);
MXS_FREE(map->database);
MXS_FREE(map->table);
MXS_FREE(map);
map = NULL;
}
}
return map;
}
/**
* @brief Free a table map
* @param map Table map to free
*/
void table_map_free(TABLE_MAP *map)
{
if (map)
{
MXS_FREE(map->column_types);
MXS_FREE(map->database);
MXS_FREE(map->table);
MXS_FREE(map);
}
}
/**
* @brief Map a table to a different ID
*
* This updates the table ID that the @c TABLE_MAP object is assigned with
*
* @param ptr Pointer to the start of a table map event
* @param hdr_len Post-header length
* @param map Table map to remap
*/
void table_map_remap(uint8_t *ptr, uint8_t hdr_len, TABLE_MAP *map)
{
uint64_t table_id = 0;
size_t id_size = hdr_len == 6 ? 4 : 6;
memcpy(&table_id, ptr, id_size);
map->id = table_id;
}