Files
util.nix/package/c/hemar/hemar.c

1659 lines
53 KiB
C
Executable File

/*
* hemar.c
* Template parser implementation for Hemar
*/
#include "hemar.h"
#include "postgres.h"
#include <string.h>
#include <ctype.h>
#include "utils/elog.h"
#include "utils/memutils.h"
#include "mb/pg_wchar.h"
#include "fmgr.h"
#include "utils/builtins.h"
#include "lib/stringinfo.h"
#include "utils/jsonb.h"
#include "catalog/pg_type.h"
#include "executor/spi.h"
#include "funcapi.h"
/* Forward declarations */
static char *get_jsonb_path_value(Datum jsonb_context, const char *path, bool *found);
static Datum get_jsonb_array(Datum jsonb_context, const char *path, bool *found);
static int get_jsonb_array_length(Datum jsonb_array);
static Datum get_jsonb_array_element(Datum jsonb_array, int index);
static Datum create_iterator_context(Datum parent_context, const char *iterator_name, Datum item_context);
static Datum get_jsonb_include_template(Datum jsonb_context, const char *key, bool *found);
static void get_include_data(Datum include_data, char **template_out, Datum *context_out);
static void template_node_to_string(TemplateNode *node, StringInfo result, int indent);
/* Helper function to skip whitespace */
static const char *
skip_whitespace(const char *s)
{
while (*s && isspace((unsigned char)*s))
s++;
return s;
}
/* Initialize template value based on type */
static TemplateValue
init_template_value(TemplateNodeType type)
{
TemplateValue value;
switch (type)
{
case TEMPLATE_NODE_TEXT:
value.text.content = NULL;
break;
case TEMPLATE_NODE_INTERPOLATE:
value.interpolate.key = NULL;
break;
case TEMPLATE_NODE_SECTION:
value.section.iterator = NULL;
value.section.collection = NULL;
value.section.body = NULL;
break;
case TEMPLATE_NODE_EXECUTE:
value.execute.code = NULL;
break;
case TEMPLATE_NODE_INCLUDE:
value.include.key = NULL;
break;
default:
elog(ERROR, "Unknown template node type: %d", type);
/* This won't be reached due to elog(ERROR) */
memset(&value, 0, sizeof(value));
break;
}
return value;
}
/* Initialize a new template node */
static TemplateNode *
init_template_node(MemoryContext context, TemplateNodeType type)
{
TemplateNode *node;
node = (TemplateNode *) MemoryContextAlloc(context, sizeof(TemplateNode));
node->next = NULL;
node->type = type;
node->value = (TemplateValue *) MemoryContextAlloc(context, sizeof(TemplateValue));
*node->value = init_template_value(type);
return node;
}
/* Error code to string conversion */
const char *
template_error_to_string(TemplateErrorCode code)
{
switch (code)
{
case TEMPLATE_ERROR_NONE:
return "No error";
case TEMPLATE_ERROR_UNKNOWN_TAG:
return "Unknown tag";
case TEMPLATE_ERROR_NESTED_INTERPOLATION:
return "Nested interpolation";
case TEMPLATE_ERROR_NESTED_SECTION_ITERATOR:
return "Nested section iterator";
case TEMPLATE_ERROR_UNEXPECTED_SECTION_END:
return "Unexpected section end";
case TEMPLATE_ERROR_NESTED_INCLUDE:
return "Nested include";
case TEMPLATE_ERROR_NESTED_EXECUTE:
return "Nested execute";
case TEMPLATE_ERROR_INVALID_CONFIG:
return "Invalid config";
case TEMPLATE_ERROR_OUT_OF_MEMORY:
return "Out of memory";
case TEMPLATE_ERROR_UNEXPECTED_INCLUDE_END:
return "Unexpected include end";
case TEMPLATE_ERROR_UNEXPECTED_EXECUTE_END:
return "Unexpected execute end";
default:
return "Unknown error";
}
}
/* Default template configuration */
TemplateConfig
template_default_config(MemoryContext context)
{
TemplateConfig config;
config.Syntax.Braces.open = "{%";
config.Syntax.Braces.close = "%}";
config.Syntax.Section.control = "for ";
config.Syntax.Section.source = "in ";
config.Syntax.Section.begin = "do ";
config.Syntax.Interpolate.invoke = "";
config.Syntax.Include.invoke = "include ";
config.Syntax.Execute.invoke = "exec ";
config.Syntax.nesting = "->";
return config;
}
/* Validate template configuration */
bool
template_validate_config(const TemplateConfig *config, TemplateErrorCode *error_code)
{
if (!config)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check open brace */
if (!config->Syntax.Braces.open || strlen(config->Syntax.Braces.open) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check close brace */
if (!config->Syntax.Braces.close || strlen(config->Syntax.Braces.close) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check section control */
if (!config->Syntax.Section.control || strlen(config->Syntax.Section.control) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check section source */
if (!config->Syntax.Section.source || strlen(config->Syntax.Section.source) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check section begin */
if (!config->Syntax.Section.begin || strlen(config->Syntax.Section.begin) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check interpolate invoke */
if (!config->Syntax.Interpolate.invoke || strlen(config->Syntax.Interpolate.invoke) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check include invoke */
if (!config->Syntax.Include.invoke || strlen(config->Syntax.Include.invoke) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check execute invoke */
if (!config->Syntax.Execute.invoke || strlen(config->Syntax.Execute.invoke) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
/* Check nesting */
if (!config->Syntax.nesting || strlen(config->Syntax.nesting) > TEMPLATE_MAX_PREFIX_LEN)
{
if (error_code)
*error_code = TEMPLATE_ERROR_INVALID_CONFIG;
return false;
}
if (error_code)
*error_code = TEMPLATE_ERROR_NONE;
return true;
}
/* Parse interpolation tag */
static TemplateNode *
template_parse_interpolation(MemoryContext context, const char **s_ptr,
const TemplateConfig *config, TemplateErrorCode *error_code)
{
const char **s = s_ptr;
const char *key_start;
size_t key_len;
TemplateNode *node;
node = init_template_node(context, TEMPLATE_NODE_INTERPOLATE);
/* Skip to the content */
*s += strlen(config->Syntax.Braces.open);
*s = skip_whitespace(*s);
*s += strlen(config->Syntax.Interpolate.invoke);
*s = skip_whitespace(*s);
key_start = *s;
while (**s != '\0')
{
if (isspace((unsigned char)**s) ||
strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
break;
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_NESTED_INTERPOLATION;
template_free_node(node);
return NULL;
}
(*s)++;
}
key_len = *s - key_start;
node->value->interpolate.key = MemoryContextStrdup(context, pnstrdup(key_start, key_len));
*s = skip_whitespace(*s);
/* Check for closing brace */
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
*s_ptr = *s + strlen(config->Syntax.Braces.close);
return node;
}
/* Parse section tag */
static TemplateNode *
template_parse_section(MemoryContext context, const char **s_ptr,
const TemplateConfig *config, TemplateErrorCode *error_code)
{
const char **s = s_ptr;
const char *iterator_start, *collection_start;
size_t iterator_len, collection_len;
TemplateNode *node, *body_node;
node = init_template_node(context, TEMPLATE_NODE_SECTION);
/* Skip to the content */
*s += strlen(config->Syntax.Braces.open);
*s = skip_whitespace(*s);
*s += strlen(config->Syntax.Section.control);
/* Find the iterator name */
*s = skip_whitespace(*s);
iterator_start = *s;
while (**s != '\0')
{
if (isspace((unsigned char)**s) ||
strncmp(*s, config->Syntax.Section.source, strlen(config->Syntax.Section.source)) == 0)
break;
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_NESTED_SECTION_ITERATOR;
template_free_node(node);
return NULL;
}
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
(*s)++;
}
iterator_len = *s - iterator_start;
node->value->section.iterator = MemoryContextStrdup(context, pnstrdup(iterator_start, iterator_len));
/* Find the collection name */
*s = skip_whitespace(*s);
if (strncmp(*s, config->Syntax.Section.source, strlen(config->Syntax.Section.source)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
*s += strlen(config->Syntax.Section.source);
*s = skip_whitespace(*s);
collection_start = *s;
while (**s != '\0')
{
if (isspace((unsigned char)**s) ||
strncmp(*s, config->Syntax.Section.begin, strlen(config->Syntax.Section.begin)) == 0)
break;
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_NESTED_SECTION_ITERATOR;
template_free_node(node);
return NULL;
}
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
(*s)++;
}
collection_len = *s - collection_start;
node->value->section.collection = MemoryContextStrdup(context, pnstrdup(collection_start, collection_len));
/* Check for 'do' keyword */
*s = skip_whitespace(*s);
if (strncmp(*s, config->Syntax.Section.begin, strlen(config->Syntax.Section.begin)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
*s += strlen(config->Syntax.Section.begin);
/* Parse the body */
body_node = template_parse(context, s, config, true, error_code);
if (!body_node)
{
template_free_node(node);
return NULL;
}
node->value->section.body = body_node;
/* Skip to the end of the section */
*s = skip_whitespace(*s);
/* Check for closing brace */
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_SECTION_END;
template_free_node(node);
return NULL;
}
*s_ptr = *s + strlen(config->Syntax.Braces.close);
return node;
}
/* Parse include tag */
static TemplateNode *
template_parse_include(MemoryContext context, const char **s_ptr,
const TemplateConfig *config, TemplateErrorCode *error_code)
{
const char **s = s_ptr;
const char *include_start;
size_t include_len;
TemplateNode *node;
node = init_template_node(context, TEMPLATE_NODE_INCLUDE);
/* Skip to the content */
*s += strlen(config->Syntax.Braces.open);
*s = skip_whitespace(*s);
*s += strlen(config->Syntax.Include.invoke);
*s = skip_whitespace(*s);
include_start = *s;
while (**s != '\0')
{
if (isspace((unsigned char)**s) ||
strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
break;
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_NESTED_INCLUDE;
template_free_node(node);
return NULL;
}
(*s)++;
}
include_len = *s - include_start;
node->value->include.key = MemoryContextStrdup(context, pnstrdup(include_start, include_len));
*s = skip_whitespace(*s);
/* Check for closing brace */
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_INCLUDE_END;
template_free_node(node);
return NULL;
}
*s_ptr = *s + strlen(config->Syntax.Braces.close);
return node;
}
/* Parse execute tag */
static TemplateNode *
template_parse_execute(MemoryContext context, const char **s_ptr,
const TemplateConfig *config, TemplateErrorCode *error_code)
{
const char **s = s_ptr;
const char *code_start;
size_t code_len;
TemplateNode *node;
node = init_template_node(context, TEMPLATE_NODE_EXECUTE);
/* Skip to the content */
*s += strlen(config->Syntax.Braces.open);
*s = skip_whitespace(*s);
*s += strlen(config->Syntax.Execute.invoke);
*s = skip_whitespace(*s);
code_start = *s;
while (**s != '\0')
{
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
break;
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_NESTED_EXECUTE;
template_free_node(node);
return NULL;
}
(*s)++;
}
code_len = *s - code_start;
node->value->execute.code = MemoryContextStrdup(context, pnstrdup(code_start, code_len));
/* Check for closing brace */
if (strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) != 0)
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNEXPECTED_EXECUTE_END;
template_free_node(node);
return NULL;
}
*s_ptr = *s + strlen(config->Syntax.Braces.close);
return node;
}
/* Main template parser function */
TemplateNode *
template_parse(MemoryContext context, const char **s, const TemplateConfig *config,
bool inner_parse, TemplateErrorCode *error_code)
{
const char *start;
TemplateNode *root, *current, *tag_node;
bool current_node_filled = false;
const char *tag_prefix;
size_t text_len;
if (!template_validate_config(config, error_code))
{
return NULL;
}
start = *s;
root = init_template_node(context, TEMPLATE_NODE_TEXT);
current = root;
while (*s && **s != '\0')
{
/* Check for closing brace in inner parse */
if (inner_parse && strncmp(*s, config->Syntax.Braces.close, strlen(config->Syntax.Braces.close)) == 0)
{
break;
}
if (strncmp(*s, config->Syntax.Braces.open, strlen(config->Syntax.Braces.open)) == 0)
{
/* Handle text before tag */
if (start != *s)
{
if (current_node_filled)
{
TemplateNode *new_node = init_template_node(context, TEMPLATE_NODE_TEXT);
current->next = new_node;
current = new_node;
}
else
{
current->type = TEMPLATE_NODE_TEXT;
*current->value = init_template_value(TEMPLATE_NODE_TEXT);
}
text_len = *s - start;
current->value->text.content = MemoryContextStrdup(context, pnstrdup(start, text_len));
current_node_filled = true;
}
/* Parse the tag */
tag_node = NULL;
tag_prefix = *s + strlen(config->Syntax.Braces.open);
tag_prefix = skip_whitespace(tag_prefix);
/* Determine tag type by prefix */
if (strncmp(tag_prefix, config->Syntax.Section.control, strlen(config->Syntax.Section.control)) == 0)
{
tag_node = template_parse_section(context, s, config, error_code);
}
else if (strncmp(tag_prefix, config->Syntax.Include.invoke, strlen(config->Syntax.Include.invoke)) == 0)
{
tag_node = template_parse_include(context, s, config, error_code);
}
else if (strncmp(tag_prefix, config->Syntax.Execute.invoke, strlen(config->Syntax.Execute.invoke)) == 0)
{
tag_node = template_parse_execute(context, s, config, error_code);
}
else if (strncmp(tag_prefix, config->Syntax.Interpolate.invoke, strlen(config->Syntax.Interpolate.invoke)) == 0)
{
tag_node = template_parse_interpolation(context, s, config, error_code);
}
else
{
if (error_code)
*error_code = TEMPLATE_ERROR_UNKNOWN_TAG;
template_free_node(root);
return NULL;
}
if (!tag_node)
{
template_free_node(root);
return NULL;
}
if (current_node_filled)
{
current->next = tag_node;
current = tag_node;
}
else
{
*current = *tag_node;
pfree(tag_node);
}
current_node_filled = true;
start = *s;
}
else
{
(*s)++;
}
}
/* Handle remaining text */
if (start != *s)
{
if (current_node_filled)
{
TemplateNode *new_node = init_template_node(context, TEMPLATE_NODE_TEXT);
current->next = new_node;
current = new_node;
}
else
{
current->type = TEMPLATE_NODE_TEXT;
*current->value = init_template_value(TEMPLATE_NODE_TEXT);
}
text_len = *s - start;
current->value->text.content = MemoryContextStrdup(context, pnstrdup(start, text_len));
current_node_filled = true;
}
/* If no nodes were created, ensure we have at least an empty text node */
if (!current_node_filled)
{
current->type = TEMPLATE_NODE_TEXT;
*current->value = init_template_value(TEMPLATE_NODE_TEXT);
current->value->text.content = MemoryContextStrdup(context, "");
}
if (error_code)
*error_code = TEMPLATE_ERROR_NONE;
return root;
}
/* Free a template node and all its children */
void
template_free_node(TemplateNode *node)
{
TemplateNode *current, *next;
if (!node)
return;
current = node;
while (current)
{
next = current->next;
if (current->value)
{
switch (current->type)
{
case TEMPLATE_NODE_TEXT:
if (current->value->text.content)
pfree(current->value->text.content);
break;
case TEMPLATE_NODE_INTERPOLATE:
if (current->value->interpolate.key)
pfree(current->value->interpolate.key);
break;
case TEMPLATE_NODE_SECTION:
if (current->value->section.iterator)
pfree(current->value->section.iterator);
if (current->value->section.collection)
pfree(current->value->section.collection);
if (current->value->section.body)
template_free_node(current->value->section.body);
break;
case TEMPLATE_NODE_EXECUTE:
if (current->value->execute.code)
pfree(current->value->execute.code);
break;
case TEMPLATE_NODE_INCLUDE:
if (current->value->include.key)
pfree(current->value->include.key);
break;
default:
/* Should not happen */
break;
}
pfree(current->value);
}
pfree(current);
current = next;
}
}
/* Render a template with the given context */
static char *
template_render(MemoryContext context, TemplateNode *node, Datum jsonb_context, bool *error)
{
StringInfoData result;
TemplateNode *current;
if (!node || !context || error == NULL)
{
if (error)
*error = true;
return NULL;
}
*error = false;
initStringInfo(&result);
current = node;
while (current)
{
switch (current->type)
{
case TEMPLATE_NODE_TEXT:
if (current->value->text.content)
appendStringInfoString(&result, current->value->text.content);
break;
case TEMPLATE_NODE_INTERPOLATE:
{
char *value = NULL;
bool found = false;
if (current->value->interpolate.key)
{
/* Extract value from JSONB context */
value = get_jsonb_path_value(jsonb_context, current->value->interpolate.key, &found);
if (found && value)
{
appendStringInfoString(&result, value);
pfree(value);
}
}
}
break;
case TEMPLATE_NODE_SECTION:
{
/* Handle sections (loops) */
char *collection_path = current->value->section.collection;
Datum array_value;
bool found = false;
int array_length;
int i;
if (collection_path && current->value->section.body)
{
/* Get array from context */
array_value = get_jsonb_array(jsonb_context, collection_path, &found);
if (found)
{
array_length = get_jsonb_array_length(array_value);
/* Handle empty arrays gracefully */
if (array_length <= 0)
break;
for (i = 0; i < array_length; i++)
{
Datum item_context = get_jsonb_array_element(array_value, i);
Datum merged_context;
char *item_result;
bool item_error = false;
if (item_context == (Datum) 0)
{
/* Create an empty object for null array elements */
JsonbParseState *parse_state = NULL;
JsonbValue *empty_obj;
pushJsonbValue(&parse_state, WJB_BEGIN_OBJECT, NULL);
empty_obj = pushJsonbValue(&parse_state, WJB_END_OBJECT, NULL);
item_context = PointerGetDatum(JsonbValueToJsonb(empty_obj));
}
/* Create context with iterator variable */
merged_context = create_iterator_context(jsonb_context, current->value->section.iterator, item_context);
if (merged_context == (Datum) 0)
continue;
/* Render section body with new context */
item_result = template_render(context, current->value->section.body, merged_context, &item_error);
if (!item_error && item_result)
{
appendStringInfoString(&result, item_result);
pfree(item_result);
}
else if (item_error)
{
*error = true;
return result.data;
}
}
}
}
}
break;
case TEMPLATE_NODE_INCLUDE:
{
/* Handle includes */
char *template_key = current->value->include.key;
Datum include_data;
bool found = false;
if (template_key)
{
/* Find include template in context */
include_data = get_jsonb_include_template(jsonb_context, template_key, &found);
if (found)
{
char *include_template = NULL;
Datum include_context = (Datum) 0;
char *include_result;
bool include_error = false;
/* Extract template and context */
get_include_data(include_data, &include_template, &include_context);
/* Parse and render included template */
if (include_template)
{
TemplateConfig config = template_default_config(context);
TemplateErrorCode error_code;
const char *template_str = include_template;
TemplateNode *include_node = template_parse(context, &template_str, &config, false, &error_code);
if (include_node && error_code == TEMPLATE_ERROR_NONE)
{
include_result = template_render(context, include_node,
include_context != (Datum) 0 ? include_context : jsonb_context,
&include_error);
if (!include_error && include_result)
{
appendStringInfoString(&result, include_result);
pfree(include_result);
}
else
{
*error = true;
}
template_free_node(include_node);
}
else
{
*error = true;
}
pfree(include_template);
}
}
}
}
break;
case TEMPLATE_NODE_EXECUTE:
/* Execute is not implemented in this version */
break;
default:
/* Unknown node type */
break;
}
if (*error)
break;
current = current->next;
}
return result.data;
}
/* Helper functions for JSONB handling */
static char *
get_jsonb_path_value(Datum jsonb_context, const char *path, bool *found)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(jsonb_context);
JsonbValue *jbv_result;
JsonbValue key;
JsonbIterator *it;
JsonbIteratorToken token;
char *result = NULL;
*found = false;
if (!jb || !path)
return NULL;
/* Handle simple top-level key */
if (strchr(path, '.') == NULL && strchr(path, '[') == NULL)
{
key.type = jbvString;
key.val.string.val = (char *) path;
key.val.string.len = strlen(path);
jbv_result = findJsonbValueFromContainer(&jb->root, JB_FOBJECT, &key);
if (jbv_result)
{
*found = true;
if (jbv_result->type == jbvString)
{
result = pnstrdup(jbv_result->val.string.val, jbv_result->val.string.len);
}
else if (jbv_result->type == jbvNumeric)
{
Numeric num = jbv_result->val.numeric;
result = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(num)));
}
else if (jbv_result->type == jbvBool)
{
result = pstrdup(jbv_result->val.boolean ? "true" : "false");
}
else if (jbv_result->type == jbvNull)
{
result = pstrdup("");
}
else if (jbv_result->type == jbvBinary)
{
/* Convert binary type to string representation */
StringInfoData buf;
JsonbValue v;
initStringInfo(&buf);
it = JsonbIteratorInit((JsonbContainer *)&jbv_result->val.binary);
while ((token = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
{
if (token == WJB_VALUE)
{
if (v.type == jbvString)
{
appendBinaryStringInfo(&buf, v.val.string.val, v.val.string.len);
}
else if (v.type == jbvNumeric)
{
Numeric num = v.val.numeric;
char *numstr = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(num)));
appendStringInfoString(&buf, numstr);
pfree(numstr);
}
else if (v.type == jbvBool)
{
appendStringInfoString(&buf, v.val.boolean ? "true" : "false");
}
}
}
result = buf.data;
}
}
}
else
{
/* Handle nested paths using a JSON path expression */
/* This is a simplified implementation and would need to be expanded for a full solution */
char *current_path = pstrdup(path);
char *token;
char *saveptr;
JsonbValue *current_jbv;
token = strtok_r(current_path, ".", &saveptr);
while (token != NULL)
{
key.type = jbvString;
key.val.string.val = token;
key.val.string.len = strlen(token);
current_jbv = findJsonbValueFromContainer(&jb->root, JB_FOBJECT, &key);
if (!current_jbv)
{
pfree(current_path);
return NULL;
}
token = strtok_r(NULL, ".", &saveptr);
/* If there are more path segments, current value must be an object */
if (token != NULL)
{
if (current_jbv->type != jbvBinary)
{
pfree(current_path);
return NULL;
}
jb = (Jsonb *) DatumGetPointer(JsonbValueToJsonb(current_jbv));
}
else
{
/* We found the value */
*found = true;
if (current_jbv->type == jbvString)
{
result = pnstrdup(current_jbv->val.string.val, current_jbv->val.string.len);
}
else if (current_jbv->type == jbvNumeric)
{
Numeric num = current_jbv->val.numeric;
result = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(num)));
}
else if (current_jbv->type == jbvBool)
{
result = pstrdup(current_jbv->val.boolean ? "true" : "false");
}
else if (current_jbv->type == jbvNull)
{
result = pstrdup("");
}
}
}
pfree(current_path);
}
return result;
}
static Datum
get_jsonb_array(Datum jsonb_context, const char *path, bool *found)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(jsonb_context);
JsonbValue *jbv_result;
JsonbValue key;
Datum result = (Datum) 0;
*found = false;
if (!jb || !path)
return result;
/* Handle simple top-level key */
if (strchr(path, '.') == NULL)
{
key.type = jbvString;
key.val.string.val = (char *) path;
key.val.string.len = strlen(path);
jbv_result = findJsonbValueFromContainer(&jb->root, JB_FOBJECT, &key);
if (jbv_result && jbv_result->type == jbvBinary)
{
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
it = JsonbIteratorInit((JsonbContainer *)&jbv_result->val.binary);
token = JsonbIteratorNext(&it, &v, false);
if (token == WJB_BEGIN_ARRAY)
{
*found = true;
result = PointerGetDatum(JsonbValueToJsonb(jbv_result));
}
}
}
else
{
/* Handle nested paths */
/* This is a simplified implementation */
char *current_path = pstrdup(path);
char *token;
char *saveptr;
JsonbValue *current_jbv;
token = strtok_r(current_path, ".", &saveptr);
while (token != NULL)
{
key.type = jbvString;
key.val.string.val = token;
key.val.string.len = strlen(token);
current_jbv = findJsonbValueFromContainer(&jb->root, JB_FOBJECT, &key);
if (!current_jbv)
{
pfree(current_path);
return result;
}
token = strtok_r(NULL, ".", &saveptr);
/* If there are more path segments, current value must be an object */
if (token != NULL)
{
if (current_jbv->type != jbvBinary)
{
pfree(current_path);
return result;
}
jb = (Jsonb *) DatumGetPointer(JsonbValueToJsonb(current_jbv));
}
else
{
/* Check if the final value is an array */
if (current_jbv->type == jbvBinary)
{
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
it = JsonbIteratorInit((JsonbContainer *)&current_jbv->val.binary);
token = JsonbIteratorNext(&it, &v, false);
if (token == WJB_BEGIN_ARRAY)
{
*found = true;
result = PointerGetDatum(JsonbValueToJsonb(current_jbv));
}
}
}
}
pfree(current_path);
}
return result;
}
static int
get_jsonb_array_length(Datum jsonb_array)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(jsonb_array);
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
int count = 0;
if (!jb)
return 0;
it = JsonbIteratorInit((JsonbContainer *)&jb->root);
/* Skip the WJB_BEGIN_ARRAY token */
token = JsonbIteratorNext(&it, &v, false);
if (token != WJB_BEGIN_ARRAY)
return 0;
/* Count array elements */
while ((token = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
{
if (token == WJB_ELEM)
count++;
}
return count;
}
static Datum
get_jsonb_array_element(Datum jsonb_array, int index)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(jsonb_array);
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
int current_index = 0;
Datum result = (Datum) 0;
JsonbParseState *parse_state = NULL;
JsonbValue *jbv_result;
if (!jb || index < 0)
return result;
it = JsonbIteratorInit((JsonbContainer *)&jb->root);
/* Skip the WJB_BEGIN_ARRAY token */
token = JsonbIteratorNext(&it, &v, false);
if (token != WJB_BEGIN_ARRAY)
return result;
/* Find the element at the specified index */
while ((token = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
{
if (token == WJB_ELEM)
{
if (current_index == index)
{
/* Found the element */
if (v.type == jbvBinary)
{
/* For binary values, just convert directly */
result = PointerGetDatum(JsonbValueToJsonb(&v));
}
else
{
/* For scalar values, we need to create a proper JSON value */
pushJsonbValue(&parse_state, WJB_BEGIN_OBJECT, NULL);
/* Add a dummy key "value" */
JsonbValue key;
key.type = jbvString;
key.val.string.val = "value";
key.val.string.len = 5;
pushJsonbValue(&parse_state, WJB_KEY, &key);
/* Add the value */
pushJsonbValue(&parse_state, WJB_VALUE, &v);
/* Finish the object */
jbv_result = pushJsonbValue(&parse_state, WJB_END_OBJECT, NULL);
/* Convert to Jsonb */
result = PointerGetDatum(JsonbValueToJsonb(jbv_result));
}
break;
}
current_index++;
}
}
return result;
}
static Datum
create_iterator_context(Datum parent_context, const char *iterator_name, Datum item_context)
{
Jsonb *parent_jb = (Jsonb *) DatumGetPointer(parent_context);
Jsonb *item_jb = (Jsonb *) DatumGetPointer(item_context);
JsonbParseState *parse_state = NULL;
JsonbValue *result;
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
JsonbValue key;
JsonbValue val;
bool is_scalar = false;
if (!parent_jb || !item_jb || !iterator_name)
return parent_context;
/* Start with a copy of the parent context */
pushJsonbValue(&parse_state, WJB_BEGIN_OBJECT, NULL);
/* Copy all fields from parent context */
it = JsonbIteratorInit((JsonbContainer *)&parent_jb->root);
/* Skip the WJB_BEGIN_OBJECT token */
token = JsonbIteratorNext(&it, &v, false);
if (token != WJB_BEGIN_OBJECT)
return parent_context;
/* Copy all key-value pairs from parent */
while ((token = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
{
if (token == WJB_KEY)
{
/* Copy the key */
key.type = jbvString;
key.val.string.val = pnstrdup(v.val.string.val, v.val.string.len);
key.val.string.len = v.val.string.len;
pushJsonbValue(&parse_state, WJB_KEY, &key);
/* Get and copy the value */
token = JsonbIteratorNext(&it, &val, false);
pushJsonbValue(&parse_state, WJB_VALUE, &val);
pfree(key.val.string.val);
}
}
/* Add the iterator variable */
key.type = jbvString;
key.val.string.val = (char *) iterator_name;
key.val.string.len = strlen(iterator_name);
pushJsonbValue(&parse_state, WJB_KEY, &key);
/* Check if the item is a scalar value wrapped in an object */
it = JsonbIteratorInit((JsonbContainer *)&item_jb->root);
token = JsonbIteratorNext(&it, &v, false);
if (token == WJB_BEGIN_OBJECT)
{
/* Check if it's our special scalar wrapper with "value" key */
token = JsonbIteratorNext(&it, &v, false);
if (token == WJB_KEY && v.type == jbvString &&
v.val.string.len == 5 && strncmp(v.val.string.val, "value", 5) == 0)
{
/* Get the scalar value */
token = JsonbIteratorNext(&it, &v, false);
if (token == WJB_VALUE)
{
is_scalar = true;
pushJsonbValue(&parse_state, WJB_VALUE, &v);
}
}
}
/* If not a scalar, use the whole item as is */
if (!is_scalar)
{
it = JsonbIteratorInit((JsonbContainer *)&item_jb->root);
token = JsonbIteratorNext(&it, &v, false);
pushJsonbValue(&parse_state, WJB_VALUE, &v);
}
/* Finalize the new context object */
result = pushJsonbValue(&parse_state, WJB_END_OBJECT, NULL);
return PointerGetDatum(JsonbValueToJsonb(result));
}
static Datum
get_jsonb_include_template(Datum jsonb_context, const char *key, bool *found)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(jsonb_context);
JsonbValue *jbv_result;
JsonbValue search_key;
Datum result = (Datum) 0;
char *include_key;
*found = false;
if (!jb || !key)
return result;
/* Construct the include key */
include_key = psprintf("include %s", key);
/* Look for the include template in the context */
search_key.type = jbvString;
search_key.val.string.val = include_key;
search_key.val.string.len = strlen(include_key);
jbv_result = findJsonbValueFromContainer(&jb->root, JB_FOBJECT, &search_key);
if (jbv_result && jbv_result->type == jbvBinary)
{
*found = true;
result = PointerGetDatum(JsonbValueToJsonb(jbv_result));
}
pfree(include_key);
return result;
}
static void
get_include_data(Datum include_data, char **template_out, Datum *context_out)
{
Jsonb *jb = (Jsonb *) DatumGetPointer(include_data);
JsonbIterator *it;
JsonbValue v;
JsonbIteratorToken token;
JsonbValue template_key, context_key;
JsonbValue *template_jbv, *context_jbv;
*template_out = NULL;
*context_out = (Datum) 0;
if (!jb)
return;
/* Check if it's an array of include objects */
it = JsonbIteratorInit((JsonbContainer *)&jb->root);
token = JsonbIteratorNext(&it, &v, false);
if (token != WJB_BEGIN_ARRAY)
return;
/* Get the first element (we only support one include for now) */
token = JsonbIteratorNext(&it, &v, false);
if (token != WJB_ELEM || v.type != jbvBinary)
return;
/* Get the include object */
Jsonb *include_obj = (Jsonb *) DatumGetPointer(JsonbValueToJsonb(&v));
/* Look for template and context keys */
template_key.type = jbvString;
template_key.val.string.val = "template";
template_key.val.string.len = strlen("template");
context_key.type = jbvString;
context_key.val.string.val = "context";
context_key.val.string.len = strlen("context");
template_jbv = findJsonbValueFromContainer(&include_obj->root, JB_FOBJECT, &template_key);
/* Extract template string */
if (template_jbv && template_jbv->type == jbvString)
{
*template_out = pnstrdup(template_jbv->val.string.val, template_jbv->val.string.len);
}
context_jbv = findJsonbValueFromContainer(&include_obj->root, JB_FOBJECT, &context_key);
/* Extract context object */
if (context_jbv && context_jbv->type == jbvBinary)
{
*context_out = PointerGetDatum(JsonbValueToJsonb(context_jbv));
}
}
/* PostgreSQL function wrappers */
PG_MODULE_MAGIC;
PG_FUNCTION_INFO_V1(pg_template_parse);
Datum
pg_template_parse(PG_FUNCTION_ARGS)
{
text *template_text = PG_GETARG_TEXT_PP(0);
char *template_str = text_to_cstring(template_text);
const char *template_ptr = template_str;
MemoryContext old_context;
MemoryContext parse_context;
TemplateConfig config;
TemplateNode *root = NULL;
TemplateErrorCode error_code = TEMPLATE_ERROR_NONE;
text *result_text = NULL;
StringInfoData result;
/* Create a memory context for parsing */
parse_context = AllocSetContextCreate(CurrentMemoryContext,
"Template Parse Context",
ALLOCSET_DEFAULT_SIZES);
/* Switch to the new context for parsing */
old_context = MemoryContextSwitchTo(parse_context);
/* Initialize default config */
config = template_default_config(parse_context);
PG_TRY();
{
/* Parse the template */
root = template_parse(parse_context, &template_ptr, &config, false, &error_code);
/* Check for parsing errors */
if (error_code != TEMPLATE_ERROR_NONE || !root)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("Template parsing error: %s", template_error_to_string(error_code))));
}
/* Convert the parsed template to a string representation for debugging */
initStringInfo(&result);
appendStringInfo(&result, "Template parsed successfully. Structure:\n");
template_node_to_string(root, &result, 0);
/* Switch back to the original memory context */
MemoryContextSwitchTo(old_context);
/* Return the result */
result_text = cstring_to_text(result.data);
pfree(result.data);
}
PG_CATCH();
{
/* Switch back to the original memory context for error handling */
MemoryContextSwitchTo(old_context);
/* Clean up */
if (template_str)
pfree(template_str);
/* Delete the parse context */
MemoryContextDelete(parse_context);
PG_RE_THROW();
}
PG_END_TRY();
/* Clean up */
MemoryContextDelete(parse_context);
pfree(template_str);
PG_RETURN_TEXT_P(result_text);
}
PG_FUNCTION_INFO_V1(pg_render);
Datum
pg_render(PG_FUNCTION_ARGS)
{
text *template_text = PG_GETARG_TEXT_PP(1);
Jsonb *context_jsonb = PG_GETARG_JSONB_P(0);
char *template_str = text_to_cstring(template_text);
const char *template_ptr = template_str;
MemoryContext old_context;
MemoryContext render_context;
TemplateConfig config;
TemplateNode *root = NULL;
TemplateErrorCode error_code = TEMPLATE_ERROR_NONE;
bool render_error = false;
char *rendered_result = NULL;
text *result_text = NULL;
/* Create a memory context for rendering */
render_context = AllocSetContextCreate(CurrentMemoryContext,
"Template Render Context",
ALLOCSET_DEFAULT_SIZES);
/* Switch to the new context for parsing and rendering */
old_context = MemoryContextSwitchTo(render_context);
/* Initialize default config */
config = template_default_config(render_context);
PG_TRY();
{
/* Parse the template */
root = template_parse(render_context, &template_ptr, &config, false, &error_code);
/* Check for parsing errors */
if (error_code != TEMPLATE_ERROR_NONE || !root)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("Template parsing error: %s", template_error_to_string(error_code))));
}
/* Render the template with the provided context */
rendered_result = template_render(render_context, root, PointerGetDatum(context_jsonb), &render_error);
/* Check for rendering errors */
if (render_error || !rendered_result)
{
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("Template rendering error")));
}
/* Convert the result to a text datum in the original memory context */
MemoryContextSwitchTo(old_context);
result_text = cstring_to_text(rendered_result);
}
PG_CATCH();
{
/* Switch back to the original memory context for error handling */
MemoryContextSwitchTo(old_context);
/* Clean up */
if (template_str)
pfree(template_str);
/* Delete the render context */
MemoryContextDelete(render_context);
PG_RE_THROW();
}
PG_END_TRY();
/* Clean up */
MemoryContextDelete(render_context);
pfree(template_str);
PG_RETURN_TEXT_P(result_text);
}
/* Helper function to convert template node to string for debugging */
static void
template_node_to_string(TemplateNode *node, StringInfo result, int indent)
{
TemplateNode *current = node;
int i;
while (current)
{
/* Add indentation */
for (i = 0; i < indent; i++)
appendStringInfoChar(result, ' ');
/* Add node type */
switch (current->type)
{
case TEMPLATE_NODE_TEXT:
appendStringInfo(result, "TEXT: \"%s\"\n",
current->value->text.content ? current->value->text.content : "");
break;
case TEMPLATE_NODE_INTERPOLATE:
appendStringInfo(result, "INTERPOLATE: \"%s\"\n",
current->value->interpolate.key ? current->value->interpolate.key : "");
break;
case TEMPLATE_NODE_SECTION:
appendStringInfo(result, "SECTION: iterator=\"%s\", collection=\"%s\"\n",
current->value->section.iterator ? current->value->section.iterator : "",
current->value->section.collection ? current->value->section.collection : "");
if (current->value->section.body)
{
template_node_to_string(current->value->section.body, result, indent + 2);
}
break;
case TEMPLATE_NODE_EXECUTE:
appendStringInfo(result, "EXECUTE: \"%s\"\n",
current->value->execute.code ? current->value->execute.code : "");
break;
case TEMPLATE_NODE_INCLUDE:
appendStringInfo(result, "INCLUDE: \"%s\"\n",
current->value->include.key ? current->value->include.key : "");
break;
default:
appendStringInfo(result, "UNKNOWN NODE TYPE: %d\n", current->type);
break;
}
current = current->next;
}
}